Control Box Replacement Questions

[Juniper Jane]

Hello there,

I am a newbie and have some questions if anyone may be able to help

I have a 625 foot well with the pump set at 605 feet.
It has a 2 HP motor with a 5 GPM pump.
The first pump died about 6 months ago and was replaced (by driller) with a new pump and motor.
The original 2HP 230Amp control box was not changed.
A couple months later the control box started acting up (capacitors/relay, the usual) so we called the drillers.

Drillers have now replaced the original control 2 HP control box with a 5 HP control box.
We noticed that there are 2 run capacitors and a gigantic start capacitor in this new 5HP box whereas the old 2 HP box had 1 run capacitor and 1 Start Capacitor and a relay of course.

Wondering why the driller would use a larger HP box with larger start and run caps - should I be concerned? I have read a lot on the internet about capacitors and have some concern the larger ones installed could eventually harm the motor. ??!!??

Ideas and input would be greatly appreciated! If I left anything out, please ask as I am a newbie to wells.

Thank you all

 

[Valveman]

You are correct that you do not want a 5HP box on a 2HP pump. It is OK just to see if you can jump start a locked up 2HP, but the extra capacitors are not good for the motor. Plus the overload in a 5HP box is set at like 28 amps, which is way too big for a 12-14 amp 2HP and won't trip if needed.

 

[Sponsor]

 

[Juniper Jane]

You are correct that you do not want a 5HP box on a 2HP pump. It is OK just to see if you can jump start a locked up 2HP, but the extra capacitors are not good for the motor. Plus the overload in a 5HP box is set at like 28 amps, which is way too big for a 12-14 amp 2HP and won't trip if needed.

There is also a Franklin Pumptec Plus protection box between the power panel and new 5 HP control box. I was told it should provide all protection needed ???

Could they be trying to hide something? I ask because once I had a refrigerator repair man put a "quick start" type capacitor on my dying refrigerator to get it some extra life time. Something sounds hokey to me - maybe they are trying to smooth over a bigger problem.

One other question: In reviewing my paperwork from the driller it states they used 400' of #8 wire and 220' of #10 wire. It was multi strand wires (not solid) insulated with a flat covering. The book that came with the motor has a chart in it that states solid #6 wire all the way down. Could this splice of two different wire sizes have any affect on the pump that this "larger" control box might take care of? So, in a nutshell, does this wire they installed size seem sufficient and adequate for the needs of the motor?

Sorry for so many questions (I have more) but this is my first well and I am hoping I wasn't taken advantage of because I am an older woman with little experience in this area.

Thank you for all input!

 

[Reach4]

One other question: In reviewing my paperwork from the driller it states they used 400' of #8 wire and 220' of #10 wire. It was multi strand wires (not solid) insulated with a flat covering. The book that came with the motor has a chart in it that states solid #6 wire all the way down. Could this splice of two different wire sizes have any affect on the pump that this "larger" control box might take care of? So, in a nutshell, does this wire they installed size seem sufficient and adequate for the needs of the motor?

CORRECTION
No.

I went through the procedure described on page 12 of the Franklin AIM manual in the section called "Two or More Different Cable Sizes Can Be Used". Going through the numbers, for your 2HP pump, your combo of 220 ft #10 and 400 ft #8 your wire has 121 % as much voltage drop as it should.

If you changed the #10 to #8 also, you would be right at 100%.

There is some margin built into their numbers I think. Plus, your actual wire lengths in service may be less than the numbers on the bill. It may be that you pay by the spool rather than the actual wire utilized. I am not a pro.

Also, solid and stranded carry the same current. Stranded is preferred due to surviving flexing.

 

[Juniper Jane]

Yes.

I went through the procedure described on page 12 of the Franklin AIM manual in the section called "Two or More Different Cable Sizes Can Be Used". Going through the numbers, for your 2HP pump, your combo of 220 ft #10 and 400 ft #8 uses only 79% of the allowable voltage drop.

Also, solid and stranded carry the same current. Stranded is preferred due to surviving flexing.

WOW Thank you!!!

I just found the paperwork on my motor and it is a Grundfos MS4000 and the pump is a Grundfos SP 5S20-39 in case that matters.....

if its only using 79% I wonder why they would put on a larger control box?

this is a warranty issue, just wondering If that would have anything to do with it

 

[Reach4]

Sorry, but I amended my numbers above when I found my mistake. I will take a look at that pump to see if it might make a difference. Further revisions are possible, and I look forward to somebody else checking.

I suspect the box they put in was what they had on the truck.

Edit: I looked at the Grundfos lit, and it looks like they use the Franklin numbers.

One thing to consider is that they are using "230 volts" as the nominal voltage, yet normal today we have 240. So a deeper calculation would show that the amount of wire permitted should be bigger than what the tables allow for. So I suspect that going through that might say that your wire is OK in that case. You could try measuring the voltage across the inner two terminals while the pump is running to see what that reads.

 

[Juniper Jane]

Thanks so much, I will get the voltage checked on the terminals and post them once they are available. It looks like we are mostly concerned with the actual control box then. I truly appreciate all your efforts!

 

[Valveman]

The wire might be a little light, but probably OK. The pumptec is capable of being an overload for the 2HP. But the start and run capacitors for a 5HP are too large for a 2HP. Like I said, I would use that combination to help start a sanded in pump, but not on a daily basis.

 

[Juniper Jane]

You are correct that you do not want a 5HP box on a 2HP pump. It is OK just to see if you can jump start a locked up 2HP, but the extra capacitors are not good for the motor. Plus the overload in a 5HP box is set at like 28 amps, which is way too big for a 12-14 amp 2HP and won't trip if needed.

I inquired with the drilling company that installed the box as to why they used the 5HP instead of 2HP and the person in the office told me that it is quite acceptable to oversize the box but you cannot undersize the box.

I let them know my concern was with the start and run capacitor ranges being higher than the original capacitors. They said less is not good and more is okay. I am waiting for a phone call from the boss so he can explain the reasoning.

 

[Reach4]

You might see if you get anywhere with http://www.grundfos.com/service-support/support-contact/contact.html if you don't get a reasonable response. You would make clear that you had already taken it up with the seller, and that you are concerned that the mismatch could cause a problem.

 

[Valveman]

You don't have to look very far to find that over-sizing capacitors is not a good thing. A 2HP should have a 105-126 Start Cap in 220V and a 20 MFD Run Cap. A 5HP has a 270-324 Start Cap and a 40 MFD Run Cap at 330V.

First link I found on a search. http://www.neilorme.com/Capacitors.shtml

• If the Start Cap is OVERSIZED, the high start current might burn out the start winding.

. If the Run Cap is incorrectly sized, the Power Factor will suffer, resulting in lower effeciency, higher operating costs, and possible motor damage.

 

[Juniper Jane]

You don't have to look very far to find that over-sizing capacitors is not a good thing. A 2HP should have a 105-126 Start Cap in 220V and a 20 MFD Run Cap. A 5HP has a 270-324 Start Cap and a 40 MFD Run Cap at 330V.

First link I found on a search. http://www.neilorme.com/Capacitors.shtml

• 
  
  
  • If the Start Cap is OVERSIZED, the high start current might burn out the start winding.

. If the Run Cap is incorrectly sized, the Power Factor will suffer, resulting in lower effeciency, higher operating costs, and possible motor damage.

Thank you and that TOTALLY MAKES SENSE!

 

[Juniper Jane]

Sorry, but I amended my numbers above when I found my mistake. I will take a look at that pump to see if it might make a difference. Further revisions are possible, and I look forward to somebody else checking.

I suspect the box they put in was what they had on the truck.

Edit: I looked at the Grundfos lit, and it looks like they use the Franklin numbers.

One thing to consider is that they are using "230 volts" as the nominal voltage, yet normal today we have 240. So a deeper calculation would show that the amount of wire permitted should be bigger than what the tables allow for. So I suspect that going through that might say that your wire is OK in that case. You could try measuring the voltage across the inner two terminals while the pump is running to see what that reads.

My neighbor was kind enough to bring his multi meter - he said its Harbor Freight and not the most accurate but here are the readings:

VOLTS:
L1 = 118
L2=119
YL= 119
BK= 118
RD= 396
SW=119

AMPS: NOTE: Low readings are with clamp nearly touching the wire. High readings are from the center of the loop on the clip over meter
RED = 10.8 - 11.2
BLACK = 3.1 - 3.2
YELLOW = 10.6 - 13.4
GREEN = 0.00

I posted a pic of the open control box above (oops posted 2) and one with the cover info ....

 

[Reach4]

You would normally put one meter lead on L1 (perhaps red) and the other meter lead on L2. You probably would have read close to 238 volts. I suspect he was reading with one probe on the box or green.

Your numbers are pretty normal, except the number on the red and black lines are almost like they are swapped. That may be an effect of the big run cap.

 

[Juniper Jane]

You would normally put one meter lead on L1 (perhaps red) and the other meter lead on L2. You probably would have read close to 238 volts. I suspect he was reading with one probe on the box or green.

Your numbers are pretty normal, except the number on the red and black lines are almost like they are swapped. That may be an effect of the big run cap.

I understand the L1 and L2.

which red and black lines could be swapped? The ones listed under Volts or the ones listed under Amps?

Thanks for clarifying

 

[Reach4]

I understand the L1 and L2.

which red and black lines could be swapped? The ones listed under Volts or the ones listed under Amps?

Thanks for clarifying

Amps.

I think you should find and download the Franklin AIM manual. See table 13 for expected amps on the wires.

 

[Juniper Jane]

Amps.

I think you should find and download the Franklin AIM manual. See table 13 for expected amps on the wires.

Perfect, I will look it up and download it right now - thanks again you have been more than helpful!

 

[Juniper Jane]

okay I found it and I see exactly what you are referring to. Will check into that!

 

[Craigpump]

More than likely they carry one big box using a one size fits all mentality. As Cary pointed out, the 5 hp capacitors & overloads are too big for the 2hp motor.

No, you do not swap the red & black lines. This is a single phase system.

The Grundfos wire size chart for a 2hp, 230v single phase motor says #8 is good for a run of 620', #10, 320'.

 

[Juniper Jane]

More than likely they carry one big box using a one size fits all mentality. As Cary pointed out, the 5 hp capacitors & overloads are too big for the 2hp motor.

No, you do not swap the red & black lines. This is a single phase system.

The Grundfos wire size chart for a 2hp, 230v single phase motor says #8 is good for a run of 620', #10, 320'.

Thanks craigpump. My electrician friend went thru all my paperwork this morning and just found that chart you referenced in one of the manuals they left.

He suggested a possible fix is to pull pump, take the 220 feet of #10 wire off the bottom, hook the 400 feet #8 to the pump and splice a piece of #6 220' up to the top. This should put it in good operating range??

Comments anyone? Sound Good? Could be?

Very helpful site, glad I found it!