Residential Service Entrance Conductor Temperature Rating to Use for Capacity and 2017 NEC 310.15(B)(7)

[wwhitney]

Is it right that when a mfg specs (for example) mini split with MCA of 42A @ 230, I should be using a value of 9660 VA, but then at the end I can divide the sum of all the VA for the calculation by 240?

No, use only 120V or 240V, as appropriate.

Cheers, Wayne

 

[Rossn]

No, use only 120V or 240V, as appropriate.

Cheers, Wayne

I'm a little surprised. I've always thought as a device (e.g. motor) requires a fixed amount of power... say a motor requires 1000w at 240v (4.16A). With P=IV, and a voltage of 220V available, I would expect the motor to required the same 1000W, but 4.54A. My logic might be flawed on that.

I called Milbank this morning and spoke with a different person. Verbally, he confirmed that the equipment is rated for 90C conductors on the line side of the meter socket. I asked him to send me an e-mail to document that and he said he would, but haven't seen it yet. I'll give it a couple hours before I follow-up... could just be slow, or he is verifying something. I also looked back at photos I had of the initial install, and while I can't see the entire interior and all stickers, I don't see anything that reads "Conductor sized for 90C may be used on the line side of the meter socket"

To verify the service entrance neutral conductor size (400 MCM Al... xhhw vs xhhw-2 is unclear), I ran the standard load calc for the entire dwelling and from that another calc for neutral 220.61. For the overall load calc, I reduced the MCA on the 2nd (smaller) mini-split 20%, given MCA includes 125% factor already. Is that appropriate?

Do my neutral calcs and conductor size (2nd page) look appropriate?

Off the top of your head, do you know the required current or power for your dryer? That was the same model I was considering, but didn't find service tag specs online. No worries if you don't I can easily make a call.

Lastly, garage shop equipment. I have some equipment, which is all plug and cord and almost all 120V except the welder which is 120v (21.5A) or 230v (27A). Most of it doesn't get used very often... welder, a couple times a year. Drill presses, wood working equip, etc maybe once or twice a month. One person. Knowing 3VA/sf (1050SF) are already included (2023 NEC) and that use of EV charger use is easily observed/controlled in the garage, what is the right load to factor in?

BTW, if at any time the conversation has gone too long or I ask too many questions, I won't be offended if you need to bow out... just let me know. I really appreciate all the guidance you have provided thus far.

 

[Sponsor]

 

[wwhitney]

I'm a little surprised. I've always thought as a device (e.g. motor) requires a fixed amount of power... say a motor requires 1000w at 240v (4.16A). With P=IV, and a voltage of 220V available, I would expect the motor to required the same 1000W, but 4.54A. My logic might be flawed on that.

Motors are roughly constant power loads, but not all loads are constant power. As one example, for a truly resistive load, more voltage means more power (P = V^2/R). Anyway, the NEC specifies in 220.5(A) to use the nominal voltages of 120V and 240V.

To verify the service entrance neutral conductor size (400 MCM Al... xhhw vs xhhw-2 is unclear), I ran the standard load calc for the entire dwelling and from that another calc for neutral 220.61.

I didn't really look at your neutral load calculation, but here's how to do it: to calculate the maximum unbalanced load per 220.61(A), include only 120V 2-wire and 120/240V 3-wire loads; omit all 240V 2-wire loads. [If you're so fortunate as to have a 120/240V 3-wire load that explicitly states separate loads at 120V and 240V, treat it as two loads, one 120V 2-wire and one 240V 2-wire.] Then 220.61(B)(1) permits a 70% factor for the 120/240V 3 wire dryers and electric cooking appliances. Now take the VA, divide by 240V (this assumes the 120V loads are evenly split among the two legs, which you should pay at least minimal attention to doing), and if the answer is above 200A, you can apply a 70% factor to the portion over 200A per 220.61(B)(2).

Or typically you can just look at the ampacity difference between the ungrounded conductors and the neutral conductor, find that at least that many amps of 240V 2-wire loads (or possibly even less per 220.61(B)(2)), and conclude that your unbalanced load will necessarily be less than the neutral ampacity whenever your total load is less than the ungrounded conductor ampacity.

For the overall load calc, I reduced the MCA on the 2nd (smaller) mini-split 20%, given MCA includes 125% factor already. Is that appropriate?

Not quite. Let's say your feeder has more than one motor or HVAC unit, and for each HVAC unit the largest motor on its nameplate is the compressor RLA. Then you'd compare the Table 230.248 FLCs of all the motors to the RLAs of all the HVAC units to find the largest motor. For any HVAC unit that doesn't have the largest motor, use MCA - 25% * RLA; if an HVAC unit has the largest motor, just use its MCA. For any motor that isn't the largest motor, use the FLC; if one of the motors is the largest, use 125% * FLC.

Or alternatively, if you want to use a line item for "25% of the largest motor" and use the largest RLA/FLC on that line, then just put each motor in at 100% of FLC, and each HVAC unit in at MCA - 25% * RLA.

Off the top of your head, do you know the required current or power for your dryer?

The nameplate says "120/240V 14A 60Hz 1300W". Which is a bit unclear as 14A * 240V = 3360 VA. If you aren't subject to the 5000VA minimum, use 3360 VA.

Lastly, garage shop equipment. I have some equipment, which is all plug and cord and almost all 120V except the welder which is 120v (21.5A) or 230v (27A). Most of it doesn't get used very often... welder, a couple times a year. Drill presses, wood working equip, etc maybe once or twice a month. One person. Knowing 3VA/sf (1050SF) are already included (2023 NEC) and that use of EV charger use is easily observed/controlled in the garage, what is the right load to factor in?

Zero is defensible if all you install are NEMA 5-15 or 5-20 receptacles. If you put in a 5-30, 6-30, or 6-50 receptacle for the welder, you should probably include the welder explicitly, although see the welder chapter for some funky calculations used for welders.

Cheers, Wayne

 

[Rossn]

Motors are roughly constant power loads, but not all loads are constant power. As one example, for a truly resistive load, more voltage means more power (P = V^2/R). Anyway, the NEC specifies in 220.5(A) to use the nominal voltages of 120V and 240V.

Interesting...

I didn't really look at your neutral load calculation, but here's how to do it: to calculate the maximum unbalanced load per 220.61(A), include only 120V 2-wire and 120/240V 3-wire loads; omit all 240V 2-wire loads. [If you're so fortunate as to have a 120/240V 3-wire load that explicitly states separate loads at 120V and 240V, treat it as two loads, one 120V 2-wire and one 240V 2-wire.] Then 220.61(B)(1) permits a 70% factor for the 120/240V 3 wire dryers and electric cooking appliances. Now take the VA, divide by 240V (this assumes the 120V loads are evenly split among the two legs, which you should pay at least minimal attention to doing), and if the answer is above 200A, you can apply a 70% factor to the portion over 200A per 220.61(B)(2).

Or typically you can just look at the ampacity difference between the ungrounded conductors and the neutral conductor, find that at least that many amps of 240V 2-wire loads (or possibly even less per 220.61(B)(2)), and conclude that your unbalanced load will necessarily be less than the neutral ampacity whenever your total load is less than the ungrounded conductor ampacity.

Ok, I had not pulled out the 240 2-wire loads, as I didn't read that explicitly, but that was just my shortcoming. Even without those removed, I think 400 MCM XHHW was more than sufficient, and even more afterwards (about 200A). I'm assuming 310.12(A) 83% rule applies on the service conductor neutral as well, and at that the neutral is many times overkill. That does make sense.

Not quite. Let's say your feeder has more than one motor or HVAC unit, and for each HVAC unit the largest motor on its nameplate is the compressor RLA. Then you'd compare the Table 230.248 FLCs of all the motors to the RLAs of all the HVAC units to find the largest motor. For any HVAC unit that doesn't have the largest motor, use MCA - 25% * RLA; if an HVAC unit has the largest motor, just use its MCA. For any motor that isn't the largest motor, use the FLC; if one of the motors is the largest, use 125% * FLC.

Or alternatively, if you want to use a line item for "25% of the largest motor" and use the largest RLA/FLC on that line, then just put each motor in at 100% of FLC, and each HVAC unit in at MCA - 25% * RLA.

That makes sense.

The nameplate says "120/240V 14A 60Hz 1300W". Which is a bit unclear as 14A * 240V = 3360 VA. If you aren't subject to the 5000VA minimum, use 3360 VA.

Thanks - with these being a new class of products, not much info out there.

Zero is defensible if all you install are NEMA 5-15 or 5-20 receptacles. If you put in a 5-30, 6-30, or 6-50 receptacle for the welder, you should probably include the welder explicitly, although see the welder chapter for some funky calculations used for welders.

Cheers, Wayne

Sound good.

Heard back from a guy at the meter shop at the POCO. He seems to be telling me that 320A service is only good for 320A, continuous or non-continuous. That seems to go against the grain of what is discussed in the electrician trade forums. Maybe the derating of the service will make more sense to someone like you who knows the code well. I was just trying to get confirmation that the 320 class service does support up to 400A intermittent.

POCO: "The physical meter is only rated for 320A continuous. The meter socket is rated for 400A, 320A continuous such as what is noted for a Milbank 320A housing as example. The NEC typically requires the service to be de-rated to 80% of nameplate which is why a 400A service is noted as 320A. It is best to have discussions with the local code authority since they could have additional requirements in addition to the NEC that they are required to follow."

 

[wwhitney]

POCO: "The physical meter is only rated for 320A continuous."

If you or your neighbor have a CL320 meter already, find its make and model and look up the spec sheet on the manufacturer's website. That is more definitive that what a POCO person tells you, unless that POCO person can site a regulation they have that further limits the use of the meter. You could also check the POCO's service standards directly; PG&E publishes them all in a document called the Green Book; I expect other POCOs to similarly publish them.

My information is that both the meter and socket are rated for 320A continuous, 400A non-continuous, but that's mostly hearsay, I've never dealt directly with a service that large. In perusing UL 414, I did note that one section specified that a meter socket must handle a continuous current up to its rating, and that it optionally may allow a non-continuous current up to 125% of its rating. If the hearsay is to be believed, meter socket makers always use that option.

Cheers, Wayne

 

[Rossn]

If you or your neighbor have a CL320 meter already, find its make and model and look up the spec sheet on the manufacturer's website. That is more definitive that what a POCO person tells you, unless that POCO person can site a regulation they have that further limits the use of the meter. You could also check the POCO's service standards directly; PG&E publishes them all in a document called the Green Book; I expect other POCOs to similarly publish them.

My information is that both the meter and socket are rated for 320A continuous, 400A non-continuous, but that's mostly hearsay, I've never dealt directly with a service that large. In perusing UL 414, I did note that one section specified that a meter socket must handle a continuous current up to its rating, and that it optionally may allow a non-continuous current up to 125% of its rating. If the hearsay is to be believed, meter socket makers always use that option.

Cheers, Wayne

Thanks for letting me know I'm not too crazy. All the trade and industry folks seem very comfortable with 200A service, but once you jump into 320A service, there seems to be a lot less consistency with answers! I'm still trying to digest his comment on NEC derating of a service.

I did search the Itron site, but they only have sell sheets, not true spec sheets. I tried calling, and optioned myself to a homeowner option where they disconnected me, after telling me to contact the POCO. I suppose I'll try calling back in and find someone to press for the specs.

Ultimately, I wish I wasn't trying to jump through hoops to determine my capacity. Seems the electrician who installed the service should be able to do that clearly.

Good call on the standards guide... had not looked at that for a while. Xcel's doc mentions the below... I suspect the engineer may not be fully knowledgable, or I'm over confident.

 

[wwhitney]

Good call on the standards guide

Unfortunately the quoted section does not address your question. No explicit discussion of non-continuous loads?

Cheers, Wayne

 

[Rossn]

Unfortunately the quoted section does not address your question. No explicit discussion of non-continuous loads?

Cheers, Wayne

Nope. At least, my text search of the document only brings back the above when searching non-continuous, as well as 400 and 320.

Although it's not explicit:

doesn't imply that a 320A meters may be used up to 400A non-continuous? It seems like they wouldn't say that if they had a 320A ceiling.

 

[wwhitney]

doesn't imply that a 320A meters may be used up to 400A non-continuous?

Sorry you're right, I glanced right over that. You're good based on that info, you don't need info from the meter manufacturer.

Cheers, Wayne

 

[Rossn]

Sorry you're right, I glanced right over that. You're good based on that info, you don't need info from the meter manufacturer.

Cheers, Wayne

Ok, cool. One more obstacle overcome.

 

[Rossn]

Sorry you're right, I glanced right over that. You're good based on that info, you don't need info from the meter manufacturer.

Cheers, Wayne

Happy Halloween! I got final confirmation from Milbank, and the meter socket is rated at 75C. No real surprise there, but I was holding out some hope.

So, that puts me with a service capacity of 373.5A. But... I think I saw somewhere there may be a required ambient temperature correction?

In my case, service comes in via OH. Then 3" GRC mast to maybe a 30' horizontal run up against a soffit on the S side of the home, before it turns and goes about 3' vertical to the meter. Now all this said, I'm pretty sure most masts will see the sun and I haven't seen references to service conductors taking special consideration. And T310.15(B)(1)(2) is under the section "Conductors for General Wiring".

Do you think additional correction/adjustment factors are required in this situation? If so, do you happen to know where those are located?

 

[wwhitney]

So, that puts me with a service capacity of 373.5A. But... I think I saw somewhere there may be a required ambient temperature correction?

Yes, it's covered under 310.15(B)(1), here: (this same website will let you browse the whole NEC):

https://up.codes/viewer/colorado/nfpa-70-2023/chapter/3/wiring-methods-and-materials#310.15_%28B%29

But, ampacity correction for temperature (and adjustment for number of conductors) is not required to be done at the same time as using the temperature limits of the termination. That is, if you have 90C wire (you do), you can do the temperature correction from the 90C ampacity, compare that with the uncorrected 75C termination ampacity, and take the smaller of the two results.

So your 500 MCM Al has a 90C ampacity of 350A and a 75C ampacity of 310A. That means temperature correction will only matter if the correction factor is lower than 310/350 = 0.886. Looking at the 90C column of Table 310.15(B)(1)(1) (you need to use the 30C base table because the ampacity table 310.16 assumes 30C ambient), you are good to 104F.

For 105F to 113F, the table gives a correction factor of 0.87. But that's a simple approximation where you round up your temperature the next highest multiple of 5C. There's also a formula for a sharp answer, which I believe will tell you that you are good up to 109F. So does it regularly get above 109F outdoors where you are? E.g. for tens of hours per year?

[What percentile outdoor temperature should be used for temperature correction is not defined anywhere in the NEC. ASHRAE 99.6% outdoor temperature would probably be fine, which implies that you'd expect to see the temperature for 3.65*0.4*24 = 35 hours per year.]

Cheers, Wayne

 

[Rossn]

Yes, it's covered under 310.15(B)(1), here: (this same website will let you browse the whole NEC):

https://up.codes/viewer/colorado/nfpa-70-2023/chapter/3/wiring-methods-and-materials#310.15_%28B%29

Thanks, Wayne. I wasn't sure if service conductors had different rules than 'general wiring'.

I have usually been going straight to the NEC publication online... free access is available through a free NFPA account for those without a paid subscription.

But, ampacity correction for temperature (and adjustment for number of conductors) is not required to be done at the same time as using the temperature limits of the termination. That is, if you have 90C wire (you do), you can do the temperature correction from the 90C ampacity, compare that the uncorrected 75C termination ampacity, and take the smaller of the two results.

At one point I had read this, but since forgotten, so thank you for the re-education about the separate analysis and taking the lesser of the values.

So your 500 MCM Al has a 90C ampacity of 350A and a 75C ampacity of 310A. That means temperature correction will only matter if the correction factor is lower than 310/350 = 0.886. Looking at the 90C column of Table 310.15(B)(1)(1) (you need to use the 30C base table because the ampacity table 310.16 assumes 30C ambient), you are good to 104F.

For 105F to 113F, the table gives a correction factor of 0.87. But that's a simple approximation where you round up your temperature the next highest multiple of 5C. There's also a formula for a sharp answer, which I believe will tell you that you are good up to 109F. So does it regularly get above 109F outdoors where you are? E.g. for tens of hours per year?

We don't see those temps here in Colorado, so we should be good.

[What percentile outdoor temperature should be used for temperature correction is not defined anywhere in the NEC. ASHRAE 99.6% outdoor temperature would probably be fine, which implies that you'd expect to see the temperature for 3.65*0.4*24 = 35 hours per year.]

Cheers, Wayne

I think there are two more hurdles to clear, relating to feeder capacity. I saw a discussion over on mikeholt, but wasn't able to track it 100%. It seemed like in situations where feed-through lugs were used off the main breaker panel, there are instances where the conductors feeding the secondary may be considered a tap, which may have further conductor ampacity reductions. Now, I also understand, there are different definitions for what a feed-through lug is on a load center. In my case, these are trailer/ranch panels with the built in lugs at the bottom (end opposite main breaker) of the bus bars.

Do you think there is anything there that I have to consider around conductor ampacity for my case? To be honest, I get a little lost on the topic of taps, as I haven't really dug into them.

The second hurdle I feel pretty good about, which is thermal insulation surrounding a SER feeder for a secondary panel. If I understand correctly, per 338.10(B)(4) (for NEC 2017+), the SER can be encased in thermal building insulation without any conductor ampacity adjustments, provided a) there are two or less SER cables and b) larger than 10 gauge (not even sure they make SE 10 gauge or smaller).

Does this sound right?

Now, relating to the over all goal (determine if I can support a 50A electric heater, in addition to supplied loads), it seems like the answer is No, unless I use some type of energy management to reduced my load calculations sufficiently.

I put together this little table, including a summary of load calculations, circuits I felt were legible for adjustments through energy management, and some possible future uses requiring additional load.

For load calcs, I put an 2024 view of use and a 2027 view of use. In 2024, there isn't a well pump, second kitchen, 2nd mini-split,EVSEs, renters, etc. - even though these things are planned, and could change slightly. Also, in 2027, it's possible there isn't a hot tub, but not a given.What is clear is that the heater is probably best placed on the garage leg, as the main house leg is much more certain/solidified and nearer capacity in the near term.

Essentially, the question comes back to if I prefer:
a) leveraging energy management in 3 years to implement the electric duct heater now, which will reduce options in my back pocket for future electrical expansion without a service upgrade (which isn't going to happen). Practical energy management would be on one of the lines in green, below. Other than headroom built in to the NEC calculation, there isn't much headroom for any issues encountered.
b) using hydronics to heat the makeup airstream, and not have any energy management planned, thus preserving extra 'capacity' through energy management, should future needs arise. Also maintains a little more direct headroom over time.

For me, it's a tough call. If you have any experience/thoughts on this, would be great to hear.

I'd really like to make the electric heater work for reasons of reducing complexity (the hydronic solution will be more fiddly and potentially maintenance oriented) and dependence on fossil fuels. But, it seems that comes at the cost of not having many more tricks in the bag to support any future electrical needs.

I think tomorrow I will chat with a number of companies who have products around energy management, to get a sense of what will or won't work with my physical layout (lots of space between main and garage), and which ones seem simple+robust without crazy associated costs.

 

[wwhitney]

I have usually been going straight to the NEC publication online... free access is available through a free NFPA account for those without a paid subscription.

That's another option, but they make it hard to navigate, I assume on purpose. And it won't have any state specific amendments. While up.codes is easier to navigate, and is supposed to include any state specific amendments (it says CO uses the 2023 NEC without amendments), but you have to trust up.codes to get it right.

Do you think there is anything there that I have to consider around conductor ampacity for my case? To be honest, I get a little lost on the topic of taps, as I haven't really dug into them.

A feeder tap is simply this: a section of a feeder where the supply end of the conductor is protected by an OCPD larger than would typically be allowed, and instead a downstream OCPD is relied on to provide overload protection. Taps are allowed with various limits. But an 180A ampacity conductor protected by a 200A OCPD is not a tap, as 240.4(B) allows any 180A ampacity conductor with at most 180A of load to be protected at 200A.

Yes, 2023 NEC 338.10(B)(4) is no issue as long as you maintain spacing between cables.

Cheers, Wayne

 

[wwhitney]

Now, relating to the over all goal (determine if I can support a 50A electric heater, in addition to supplied loads)

You are clearly describing adding loads over time. So I suggest you simply look at the next phase, maybe what you call 2024, and do the load calcs for it with the 50A electric heater, assuming you want that now. If that calc works out, go ahead and install that, and install the load monitoring mentioned in 220.87.

Then by the time you get to the next phase, you'll have the real world data to tell you what the loads are actually using, and sufficient data to be able to apply 220.87. The conventional wisdom is that the load calcs for a house overestimate actual current by at least a factor of 2, so anything done under 220.87 would give you a lot more headroom.

Cheers, Wayne

 

[Rossn]

That's another option, but they make it hard to navigate, I assume on purpose. And it won't have any state specific amendments. While up.codes is easier to navigate, and is supposed to include any state specific amendments (it says CO uses the 2023 NEC without amendments), but you have to trust up.codes to get it right.

Yeah, navigation is a bit of a challenge, and not being able to copy text is no bueno. It's good to know that someone who works with this regularly feels upcodes is generally a good reference.

A feeder tap is simply this: a section of a feeder where the supply end of the conductor is protected by an OCPD larger than would typically be allowed, and instead a downstream OCPD is relied on to provide overload protection. Taps are allowed with various limits. But an 180A ampacity conductor protected by a 200A OCPD is not a tap, as 240.4(B) allows any 180A ampacity conductor with at most 180A of load to be protected at 200A.

Ok, thanks for educating me on that, as I've read a number of discussions including comments on taps, but didn't have clarity about what is classified as one.

Yes, 2023 NEC 338.10(B)(4) is no issue as long as you maintain spacing between cables.

My basement exterior walls now have another wall built inside the load bearing and stem wall, so as to be able to hit energy code effectively. Below, you can see the 250 Al SER that feeds the garage 200A subpanel... it is a long (90+') tortuous run from the main. It was a real pain to get in!

You seem to keep pulse pretty well on the online communities. Have you noticed if there are any general concerns about concealing these residential conductors in insulation, even though code allows it? I'd love to leave some space around the conductor, but also installed it in a location where insulation is also key for the structure (along the top plates)... I probably should have lowered it down a foot.

 

[Rossn]

You are clearly describing adding loads over time. So I suggest you simply look at the next phase, maybe what you call 2024, and do the load calcs for it with the 50A electric heater, assuming you want that now. If that calc works out, go ahead and install that, and install the load monitoring mentioned in 220.87.

The 2027 stuff was planned for now, as well, but I think it's going to get pushed out, as the financials on the project have gotten a little crazy... won't be a separate permit, just ultra-long running and some partial inspections. Yes, it easily fits on 2024, but knowing 2027 is quite certain means I want to count on it now and have at least a backup plan, as I won't be able to upgrade service or switch to hydronic later (new boiler won't be sized for it if I don't do it now).

Then by the time you get to the next phase, you'll have the real world data to tell you what the loads are actually using, and sufficient data to be able to apply 220.87. The conventional wisdom is that the load calcs for a house overestimate actual current by at least a factor of 2, so anything done under 220.87 would give you a lot more headroom.

I had been thinking about both what you mention, as well as the fact that we seem to be in the midst of an electrical revolution at the moment, relating to energy management options... primarily driven by home electrification and EV usage. My gut says that there will likely be some 'even better' options available come another couple years. A couple of of the EVSE makers seem to be pushing the envelope for things like power sharing or feeder/service conductor amperage monitoring, but they are still in their infancy and I am guessing this is the tip of the iceberg.

My gut says it will work out if I go the electric route... just concerned about limiting myself in the future.

Back to what you suggested... I do see the solar exclusion, but that is a few years out as well. That said, what sinks me are the big loads, and I can foresee those will see real use and keep my numbers tighter than the 2x you've mentioned a lot of homes are seeing. Ultimately, I'm guessing you are right.

 

[wwhitney]

Ok, thanks for educating me on that, as I've read a number of discussions including comments on taps, but didn't have clarity about what is classified as one.

When encountering an unfamiliar term, always check the Article 100 definition first.

You seem to keep pulse pretty well on the online communities. Have you noticed if there are any general concerns about concealing these residential conductors in insulation, even though code allows it?

I'd have no concern about insulation, but I would suggest that the 4 cables in your photo are borderline close enough to be considered bundle, and then you'd have to apply a derating for more than 3 current carrying conductors in the same conduit/cable. Particularly where you have 2 zip tied together. So I'd suggest you make an effort to "maintain spacing". One cable diameter of free space between adjacent cables seems like definitely enough.

Cheers, Wayne

 

[Rossn]

When encountering an unfamiliar term, always check the Article 100 definition first.

Noted

I'd have no concern about insulation, but I would suggest that the 4 cables in your photo are borderline close enough to be considered bundle, and then you'd have to apply a derating for more than 3 current carrying conductors in the same conduit/cable. Particularly where you have 2 zip tied together. So I'd suggest you make an effort to "maintain spacing". One cable diameter of free space between adjacent cables seems like definitely enough.

Those are mini-split insulated linesets and the per-head power cable that runs off the branch box in the laundry room (around 1A ea). They're pretty messy, and IMO not so workmanlike, but I will admit the installers had a hard job getting those down a hall and jogging a 4' offset without kinking them (hopefully). Then again, they unnecessarily hacked/destroyed one joist (structurally) that I had confirmed with both the installers and the structural engineer the hole size and placement, and pre-drilled, ust to keep things code compliant.

I only installed the one gray SER, which is a workmanlike install. Even the electrician thought it looked pretty good

Given they are linesets, and insulated, I'm assuming there is not a concern - but let me know. I suppose there could be a concern relating to when they are heating. Of course, it's a redundant heating system I don't expect to see much heating from, but I'm sure code doesn't care much about that.

 

[wwhitney]

Those are mini-split insulated linesets

Oh, OK, that makes more sense and has no bearing on the electrical. I did think the color was off. ; - ) I see the SER now just above them.

Cheers, Wayne