Help IDing these wires and box

Discussion in 'Electrical Forum discussion & Blog' started by joseph skoler, Feb 18, 2021.

  1. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    Can anyone identify these wires?

    Specifically, I see the breaker is 200 amp, but those wires look mighty big to me.

    I'm hoping I can get lucky and they'll handle 400 amp service.

    Thank you!
     

    Attached Files:

  2. fitter30

    fitter30 Well-Known Member

    Joined:
    Feb 2, 2020
    Occupation:
    Retired service tech
    Location:
    Peace valley missouri
    400 amp 1phase 400kcm cu or 600 kcm au
     
  3. Sponsor

    Sponsor Paid Advertisement

     
  4. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    Do these wires look like either 400kcm cu or 600 kcm au?

    Thank you!
     
  5. Stuff

    Stuff Well-Known Member

    Joined:
    Mar 7, 2013
    Location:
    Pennsylvania
    400 kcmil is supposed to be .632 inches in diameter and 600 kcmil is .775 in. You have aluminum wires so no, not big enough for 400 amp service.
     
    joseph skoler likes this.
  6. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    Thank you -- makes sense.

    A local electrician says 500 mcm AU is fine for 400 amps, but that I would need (or should use) 2 panels of 200 each.

    I'll probably have 2 subpanels off the main (one for the 2nd and 3rd floors; and another for guest cottages).

    Does this sound right?

    Thanks!
     
  7. Stuff

    Stuff Well-Known Member

    Joined:
    Mar 7, 2013
    Location:
    Pennsylvania
    A 400 amp panel is rare even in residential McMansions. At 400 amps things are messy. First the meter base is also referred to as 320 amps continuous. (Way too complex for me to figure out.) And then you have huge wires. So normally the meter will have dual lugs and feed two 200 amp panels in parallel, both considered service. Or if a meter-main will have dual 200 amp breakers outside that can feed two sub-panels.
     
    joseph skoler likes this.
  8. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    Got it -- thank you so much.
     
  9. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    Is that your service panel? If so, how did you deenergize it? Taking that picture with the metal tape measure while energized would be very dangerous.

    Looks like the entire panel should be replaced, given the corrosion, missing conductor insulation, etc.

    What if anything is the labeling on the sheath of the cable entering the panel?

    Cheers, Wayne
     
    Stuff likes this.
  10. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    It is my panel, and I did have to move it while energized -- very scary.

    And, yes, when I took the picture with the metal tape I realized that wasn't so smart either.

    It's all being replaced, hence this thread.

    Had an electrician over and we discussed 400 amp service -- new meter and disconnect outside, dual 200 amp panels (in parallel, I believe) in the basement.

    I'll let the pros touch the thing from now on.

    Thank you!
     
  11. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    You are very lucky, that could easily have killed you. Service conductors are effectively unfused.

    Do you have a load calculation that exceeds 200A? Otherwise the extra hassle of a 400A service is likely not worth it. NEC load calculations are very conservative, so even with a 200A load calc you'd rarely draw over 100A.

    The one exception is tankless electric water heaters, those really do need a ridiculously large service. Which is a good reason to avoid them.

    Cheers, Wayne
     
  12. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    Yes, I do know -- thank you for the concern. I won't even go into the time I touched my excavator bucket to the 10000v overhead lines and survived grabbing the iron handle twice trying to get out and then get back into the cab to shut the engine. Pretty sure the huge steel tracks grounding the machine spared my life (but it was indeed quite shocking).

    I haven't done a detailed load calculation. I don't know enough to get past the basics of appliances, lights, heating, etc., Specifically, the house is 3 floors and I think it would be good to have a subpanel for floors 2 and 3 -- I don't know if that changes the calculation or if it's just a matter of adding it all up and applying a factor.

    And, the service will also supply 3 small cottages of approx 800 sq ft each -- same question of whether the existance of subpanels changes the load calc.

    But, basically the house is 4500 sq ft and 3 cottages of 800 each for a total sq ft of 6900 -- 4 kitchens, 13 bedrooms, several play/living areas, don't know yet about heat, AC and hot water but it will either be heat pumps for heat/ac (which use electric) and propane for hot water or propane for all heat and hot water and heat pump for AC.
     
  13. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    Subpanels don't matter. You just need to add the loads.

    Since you're talking about multiple dwelling units, then there's a very good chance your load calc will exceed 200A. But a load calc for each dwelling unit is the way to start the whole design. Either teach yourself how to do it (use the alternate method) or get an electrician to do it. It's not so hard to a load calc, although I've only done it once or twice; most of the work is listing all the electrical loads, the subsequent math is simple. There should be free worksheets/spreadsheets available to help you.

    Once you have the loads, one basic design question is whether to run service conductors to each building (I assume the cottages are detached), or to run feeders. The only real advantage to running service conductors would be that you'd save one wire, so I guess feeders are probably better (haven't thought much about it).

    If you end up with (2) 200A panels, one for the cottage feeders and one for the main house, then there's no need to have them together, if you have a main disconnect by the meter. E.g. outside could be meter, main disconnect, subpanel for cottages; inside could be subpanel for the main house. Depending on the load calc, one or more large outdoor loads (A/C units) could be fed from the outdoor panel, if convenient.

    Cheers, Wayne
     
  14. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    I did a quick search and a quick fill in (meaning, I'm sure I'm incorrect about some things and missing other things), and I came to a load of 271 amps (attached).

    The idea of a 200 amp panel in the house for the inside load and an outside 200 amp panel for the house's outside load items as well as for the 3 cottages make a lot of sense.

    The cottages are detached. I understand that feeders would come off one of the 2 200 amp panels. Am I correct that service lines would have to come from the electric company and have its (or their) own meter(s)? I'd much rather have a single meter/account feeding the entire place.

    Thank you.
     
  15. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    No attachment.

    You've got basically 3 options:

    (1) One meter, one set of service conductors, one service disconnect, each cottage gets a feeder with feeder disconnect
    (2) One meter, 4 sets of service conductors, each building gets its own service disconnect
    (3) 4 meters, 4 sets of service conductors, each building gets its own service disconnect.

    Options (1) and (2) you can do on your own, the differences are all on your side of the meter. Option (3) would require the power company's involvement to set 4 different meters. But if you prefer (1) or (2), that should be fine. (1) would minimize the unfused service conductors on the property.

    Cheers, Wayne
     
  16. joseph skoler

    joseph skoler Member

    Joined:
    Jan 14, 2018
    Location:
    Sullivan County, NY
    I'm more inclined to choose #1, but probably for a poor reason: I understand it better than #2, and #3 means more coordination with the utility company, which I would prefer to minimize.

    I like the plan to put a meter/disconnect outside.

    But as I think more about it, the cottages are all on the other side of the house from the service entrance side, so the wires would need to go through anyway. So, maybe it makes more sense to put both 200a panels in the basement, a 100amp subpanel (that supplies the 2nd and 3rd floors) off one of the 200a panels, and feed both the cottages and any outdoor HVAC equipment from the 2nd 200a panel?
     
  17. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    You can arrange the subpanels however is convenient. The first question would be the load calc, for example if each cottage comes out to 70A, then you can't put all 3 in a 200A panel.

    Cheers, Wayne

    P.S. Each building needs a way to shutoff power going into the building at one location (more or less). So one thing you can't do is put a meter with no disconnect outside, and then have one 200A panel inside, and one outside. But those would be service panels, not subpanels.
     
  18. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    In most places, #3 would result in a significantly higher electric bill. In California, #3 could result in a lower bill to avoid the main house from being hit with punitive rates. Am I wrong?

    I remember watching TV shows where some villain turns off the power from outside. I always wondered how that could happen, until I found that California puts shutoffs outside.
     
  19. Stuff

    Stuff Well-Known Member

    Joined:
    Mar 7, 2013
    Location:
    Pennsylvania
    Numbers 2 and 3 can be difficult as service conductors can not run through a differeent building unless encased in 2" of concrete. Either one also requires working with the POCO's rules on what they allow.

    The 2020 NEC now requires a disconnect on the outside. Those TV villains are celebrating.

    Also you or your electrician should do the load calcs for the cottages to verify not overloading one 200 amp panel (I know it's unlikely but still need to check). https://www.mikeholt.com/documents/calculations/formulas/ResidentialLoadCalculations.xls is pretty good.
     
  20. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    A) California typically has tiered rates, so you may be right.

    B) Going forward, not just California: the 2020 NEC requires an outdoor "emergency disconnect." If you don't want villains shutting off your power easily, just put a keyed padlock on it. Those who need to operate it will either have the key or a pair of bolt cutters.

    Cheers, Wayne
     
  21. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    I expect around here, the fire department would pull the meter or cut the wires if this is a typical over head service-- not that a villain could not do that. For underground service, I expect they could enter the meter cabinet and kill service.
     
Similar Threads: Help IDing
Forum Title Date
Electrical Forum discussion & Blog Help me trace a fault? May 24, 2021
Electrical Forum discussion & Blog Switch to recess lighting - help with Romex Apr 14, 2021
Electrical Forum discussion & Blog Help converting T8 fluorescent to LED Apr 4, 2021
Electrical Forum discussion & Blog Help with Leviton Decora 3-pole smart dimmer Jan 18, 2021
Electrical Forum discussion & Blog Need help on identifying and setting up c wire Dec 12, 2020

Share This Page