100 Amp service upgrade questions.

Reply

  #1  
Old 11-23-14, 11:08 PM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
Question 100 Amp service upgrade questions.

I'll try to include as much detail as I can while keeping it simple and short.

Here is what I am working with. My parent's home is a mobile home.

Well, it used to be. Before my parent's bought it, some years ago the added garage was closed in and the rest of the house was upgraded on the outside to match. From the outside it is a home, but I can see the tin roof in the attic LOL

Anyway, since the house was added on to, and the previous owner had less electrical knowledge than I do, I will not list the mess I have stumbled upon.

What I need to do is upgrade the 100AMP breaker box inside the home to 200AMP to support the addition to the home and the central heat and air unit we hope to install.

The Central unit is rated for 20AMPS, (probably less when A/C is not in use).

The existing meter on the pole has a breaker box attached to it. The breaker box has a 200AMP MAIN and about 10 spaces for breakers.

The (service?) cable going from the breaker box on the service pole into the breaker box inside the home is buried for about 60 feet.

My questions at the moment are:

1. What size, type, rating cable do I need to purchase to run the 60ft between the two boxes to carry 200AMP service.

2. How can I tell if the currently installed cable between the two boxes is 200AMP, or 100AMP?

3. The 200AMP panel I have to install was purchased for a shop but never used. It has plenty of space for breakers. (3X the capacity of current breaker box) I plan to have each of the 7 total rooms on it's own breaker for electrical outlets (120V) With seperate runs for the 220V. (water heater, dryer, stove). I plan to set-up "zones" for lighting fixtures on seperate breakers. Now to the question: Since this was a mobile, (running the line is not going to be fun), I want to replace every inch of existing cable with new. Are there any requirements on the type of electrical wire that I can run for the mobile home?

I realize that I am asking a lot. I am a DIY'er by choice, but lately it's out of necessity. (Not so much fun that way :-) )

Any advice would be greatly appreciated.
 
Sponsored Links
  #2  
Old 11-24-14, 12:39 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
Got ahead of myself...

Kids are in bed now and I can think a little more clearly.

Based on the information I've pulled up so far, I beleive that I will need:

4/0-4/0-4/0-2/0 to run the 200AMP service from the Breaker box at the meter, (disconnect?), to the breaker box inside the home, (sub-panel?).

Is this correct? If so, would this be appropriate?:
Shop 4/0-4/0-2/0-4 Aluminum Mobile Home Feeder Service Entrance Cable (By-the-Foot) at Lowes.com

Also, looking at the sub-panel diagrams stickied to the top of this forum, I am not sure that I would need to make any changes other than upgrading the service cable entering the home and the breaker panel.

The meter box is grounded as is the disconnect. I can see where the breaker box, (sub-panel), inside the home is grounded as well, but I can't see where the ground is coming from. Are there different ground requirements for mobile homes?

All of the information that I have seen thus far states that the meter box, must be grounded, then the ground must run to the disconnect which is also ground, the the ground must run to the panel (and terminate), which is also ground. 2 of the 3 are true in my case.

I will try to contact my power company for advice, but haven't had the best experience with them in the past.
 
  #3  
Old 11-24-14, 07:41 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Just a suggestion if you have a four wire feed to the existing subpanel why not just add a second 100 amp subpanel. The 200 amp panel you have will work fine as a 100 amp subpanel. That way smaller wire from the main and less cost plus you don't have to move connections in the existing box.
 
  #4  
Old 11-24-14, 07:56 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
As mentioned, the home has had some additions. It is not drawing more than 100amps now, but we're thinking of adding a couple more rooms in the near future. With the addition of the central heat and air unit that is rated at 20 amps by itself, I would feel better with the added head room with the 200AMP subpanel.

The 100AMP panel that is currently installed in the home is the original that came in the "mobile home" from the manufacturer. It is an old Seimens and the only way to get replacement breakers for it would be to contact Seimens.

Also, it is not a four wire feed. (as far as I can tell) there is only two wires coming into the 100AMP panel. (not counting ground).

At the very least I would need to upgrade the wire from the main to the subpanel inside the home to support 200AMP. (I think)

Just to clarify. The 200AMP Disconnect is located on the service pole "outside" of the home. The cable that I am concerned about upgrading to 200AMP is between the Disconnect (outside) and the 100AMP subpanel inside the home.
 
  #5  
Old 11-24-14, 08:16 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
I agree that 200A likely is not needed, but over 60' the cost of the wire isn't that much different and you've already bought the panel. If you were to replace the panel it needs to be upgraded to a four wire feed anyway so your plan seems reasonable.

The 4/0 MHF cable is appropriate for the job. It should be sleeved in 2" PVC conduit going in and coming out of the ground to a depth of 24". The trench between the pedestal and the house should be a little more than 24" deep.

As part of this project you'll also need to upgrade the grounding of the house through some combination of city water service pipe, metal well casing and ground rods. Which do you have already? The old grounding electrode wire (earth grounding) can't be reused because it was for 100A; it needs to be at least #4 copper for 200A. If you have natural gas or propane pipes, structural steel in the old mobile home frame, or metal water pipes these will also need to be bonded (similar to grounding) with #4 copper.
 
  #6  
Old 11-24-14, 08:21 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
Another update and further clarification.

I was wrong. It is a four wire feed coming into the 100AMP subpanel inside the home.

Upon further inspection, this is what I see.

there are four wires coming in, (plus ground to the ground bus).

they are all black. three of them are the same size, one of them is smaller. They are all copper.

First is the wire going to the top of the (neutral?) white bus. It has the markings:
"AWG 8 Type MTW or THWN-2 THHN or Gasoline and Oil Resistant II or AWM 600V"

The other three wires appear to be about one and a half times larger in diameter the the first wire. No markings that I can see. One is going to the bottom of the (neutral?) white bus. The other two are going to 100AMP Main breaker. (one for each side.

When I finish a few other jobs and get the chance, I will run outside to see if there are any markings on the three wires inside the 200AMP Disconnect on the service pole.
 
  #7  
Old 11-24-14, 08:31 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
It is an old Seimens and the only way to get replacement breakers for it would be to contact Seimens.
A Type QP Siemes breaker would probably fit any older Siemens, ITE or Gould loadcenter. I have not seen a Siemens loadcenter yet that didn't use these breakers.

Shop Siemens QP 20-Amp Single-Pole Circuit Breaker at Lowes.com

seperate runs for the 220V. (water heater, dryer, stove
Is the new heat electric too? If you'll have electric heat, I'd also go with a new 200 amp feeder and panel.
 
  #8  
Old 11-24-14, 08:38 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
Thanks for the info.

There are gound rods at the service pole. I haven't found any at the home yet.

There is an unused well on the property, but to far away to be used for ground.

While doing plumbing repairs last winter, I noticed that all of the steel pipe, (unused), underneath the house has grounding wire in "several" places. I do not know if the steel pipe is for propane, (no longer in use), or if they were run from the well at some point in time.

I'm assuming that this is what was being used to ground the 100AMP panel.

The water meter is about 20ft from the home, and the pipe is PVC immediately after leaving the meter. Does the grounding have to be done "at the home"? or can it be done at the meter and buried to the home?

I can, and probably will enlist the help of a licensed electrician. Just trying to to as much as I can before I do.
 
  #9  
Old 11-24-14, 08:47 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
A Type QP Siemes breaker would probably fit any older Siemens, ITE or Gould loadcenter. I have not seen a Siemens loadcenter yet that didn't use these breakers.

Shop Siemens QP 20-Amp Single-Pole Circuit Breaker at Lowes.com
Thanks for that information, I will take a look. I have taken one of the breakers with me to all of the local hardware stores, (big and small), and nothing matched up. Maybe I will have better luck online.

Is the new heat electric too? If you'll have electric heat, I'd also go with a new 200 amp feeder and panel.
Yes. It is rated 208V-230V and 20AMPS. It is a furnace with evaporator and outisde compressor. I doubt it will draw more than 10-15 Amps when a/c is not in use.

Better safe than sorry.
 
  #10  
Old 11-24-14, 08:51 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
Does the grounding have to be done "at the home"? or can it be done at the meter and buried to the home?
Both. The 4th wire in the feeder is a ground wire from the service that terminates on an auxilliary ground bar in the panel. You must also have one or two ground rods at the home that connect with #6 copper to that same ground bar. If you have any metallic water piping likely to become energized, it must also be bonded to the ground. Most likely the steel pipe you found was for propane and that your water piping is CPVC or another plastic.

What about the heat, will it be electric?
 
  #11  
Old 11-24-14, 08:55 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
Yes. It is rated 208V-230V and 20AMPS. It is a furnace with evaporator and outisde compressor. I doubt it will draw more than 10-15 Amps when a/c is not in use.
The 20 amps sounds as if it might run a condensing unit, but it won't run electric resistance heat for a mobile with additions. Is the heat to be propane? Could it be a heat pump? Even a heat pump needs emergency back-up heat, usually it is heat strips. If it is electric, there should be a KW rating somewhere. If you have a quote, check it.

It is a furnace with evaporator and outisde compressor.
This sounds like a conventional split system. The outside unit may need 20 amps, but the furnace typically needs a separate circuit.
 
  #12  
Old 11-24-14, 08:58 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
It looks like the best approach for grounding will be to add two new ground rods at the house, six feet apart, driven to full depth. I wouldn't do anything with the old well or water meter given the distance to the house and the amount of plastic pipe in between. The old steel piping should be bonded to ground even if it is not used.
 
  #13  
Old 11-24-14, 09:01 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
Most likely the steel pipe you found was for propane and that your water piping is CPVC or another plastic.
Yes, the water piping is PVC from the Meter. It adapted to CPVC just have the first shut-of underneath the house.

I was thinking the steel piping may be propane as well, except a lot of it is buried and part that is exposed is going into the general direction of the well on the property. The well is a good 260 feet away so I'm still guessing.

What about the heat, will it be electric?
Yes
 
  #14  
Old 11-24-14, 09:06 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
What about the heat, will it be electric?
Yes
How many KW? Do you have a quote from an HVAC contractor yet? If you do, there should be something on the quote giving you that information.
 
  #15  
Old 11-24-14, 09:10 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
It is not drawing more than 100amps now, but we're thinking of adding a couple more rooms in the near future. With the addition of the central heat and air unit that is rated at 20 amps by itself, I would feel better with the added head room with the 200AMP subpanel.
I believe you misunderstood my suggestion. If you add a second panel fed with 100 amps you will have 200 amps available between the two panels. Using the 200 amp panel as a second 100 amp subpanel will give you even more spaces then if you removed the existing subpanel.

Note if the 200 amp panel has a 200 amp main breaker that does not need to be changed out because it only serves as a disconnect.
 
  #16  
Old 11-24-14, 09:16 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
The 20 amps sounds as if it might run a condensing unit, but it won't run electric resistance heat for a mobile with additions. Is the heat to be propane? Could it be a heat pump? Even a heat pump needs emergency back-up heat, usually it is heat strips. If it is electric, there should be a KW rating somewhere. If you have a quote, check it.
The heat is electric. Not sure what you mean by electric resistance or heat strips. If you mean spring-like elements, then yes. It is not a conventional mobile home unit. It was supposed to be when I picked it up in the dark. LOL When I inspected it the next morning in daylight, I saw the drip pan underneath the evaporator inside the unit. It is a horizontal unit. The evaporator is one end, the heating elements in the other end, and the fan in the center. (I planned on an attic installation, but I'll save that for another thread.

This sounds like a conventional split system. The outside unit may need 20 amps, but the furnace typically needs a separate circuit.
It is a split system. I am not experience in HVAC at all. I was going to have it professionally installed. I have yet to find a lable on either unit accept the wiring diagram on the fan housing. (Again, another thread)
 
  #17  
Old 11-24-14, 09:27 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
I believe you misunderstood my suggestion.
LOL yes and no. I understand whay you're saying, I would have the head room AND more space to add breakers/circuit with both panels.

I was more concerned with the cable between the Service Panel and the subpanel carrying the 200AMP if necessary.

And the 200AMP panel really is a "BIG" panel. If I need more breakers/circuits than I can get out of it for this house with a couple additions, I'm doing something wrong.
 
  #18  
Old 11-24-14, 09:34 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
How many KW? Do you have a quote from an HVAC contractor yet? If you do, there should be something on the quote giving you that information.
I haven't talked to a HVAC contractor yet. I just brought it home yesterday.
It is not new. I do plan to have a contractor come out in the next week or so and give a quote.
 
  #19  
Old 11-24-14, 09:39 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
The heat is electric. Not sure what you mean by electric resistance or heat strips. If you mean spring-like elements, then yes.
You are still missing my point. For example, in my area a new well insulated home needs approximately 10 watts heat per square foot with electric resistance heat. The spring like coils are electric resistance heating elements. 10 watts per square foot would mean a 10 KW furnace for a small 1,000 square foot house. Typically a 10 KW furnace needs a 240 volt, 60 amp circuit. I don't know exactly where you are located or the heating requirements there, but I suspect you need at the very least 10 KW heat. The furnace should have a label on it with the specs on the heating coils or you could check with the supplier you bought it from for the specs. The 20 amp circuit is probably just for the outside a-c condensing unit (compressor part of the system).

It is not new. I do plan to have a contractor come out in the next week or so and give a quote.
I suspect you don't know if the unit has enough heat in it for the house or not. Ask the contractor his opinion when he comes out. He'll know how to read the data plate on the furnace.
 
  #20  
Old 11-24-14, 10:04 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
LOL I understand now. Yeah, that's all over my head. And you're right it is "supposed" to have a label on it with specifications... but it doesn't. I didn't get it from a dealer, I got it from a contractor (2 hour drive) that changed out 4 units for upgrade and kept the old units.

I have to call him today to check the other units, (as they're all identical), for the lables. I will still have more faith in a local HVAC contractor.

I am located in Desoto County, MS. by the way.

I've never purchased a central furnace. This is my first time hearing about KW requirements for heating. Definately something I will check on.

It was a free unit. It may not be efficient for the home, that is yet to be determined, but I do know that it will be more efficient, and "safer" than the "space heaters" that are currently heating my parents home.

HVAC is way beyond my comprehension. My mind isn't what it used to be. I still stuff it full of useful information, it just doesn't stay there anymore.
 
  #21  
Old 11-24-14, 10:55 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
Your contractor can probably look at the unit and determine the KW rating from the elements. The worst situation would be if it doesn't have enough KW, elements can always be disconnected if you have too much. Are there any circuit breaker disconnects on the furnace such as maybe one 60 amp breaker (10 KW), two 60 amp breakers (20 KW) or one 60 and one 30 amp breakers (15 KW)?
 
  #22  
Old 11-24-14, 11:29 PM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
There are no disconnects whatsoever on the furnace

Where the wire connects inside the furnace housing, it connects the same way that ground and neutral connect to a bus in a panel. Seperated, of course, but it has holes to insert the wires, and the screw that tightens down to hold them in place.

I am still waiting on word from the contracter I got it from on the specs from the labels on the other units. I am seriously considering saving this unit for a future shop project and springing for a new one all together. I will make my decision after having an HVAC contractor inspects this one.

Thanks for all of the advice. I think I have enough information to keep me busy for a while. I am about halfway into my materials list.

One question that was nevered addressed: Are there specific reqirements for the type of wire that can be used inside the walls for mobile home distribution?

I would hate to pull all this old wire and replace it with new only to find out that it's wrong for my application, and have to do it over again.
 
  #23  
Old 11-25-14, 07:15 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
NM-b is fine in mobile homes. If you are replacing the wire you wouldn't pull it you would abandon in place by cutting as short as possible on both ends and pushing it in the walls. Long thread I missed though why you are replacing the cables.
 
  #24  
Old 11-25-14, 08:21 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
...I missed though why you are replacing the cables.
They are as old as the home. (Propery deed states it was put in place in 1976).
Wiring insulation has started to harden and crack near outlets, (recepticals and lighting).

As mentioned the existing is a HUGE mess. Current breakers are overloaded.
Since some of the wiring is beginning to fail, I'd rather go ahead and run new.
That way I full control of the circuits and, more importantly, I "know" what those circuits are.
 
  #25  
Old 11-25-14, 08:36 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
The only concern is that if your mobile home has metal studs or metal siding you're running cable through there has to be rubber/plastic grommits in the holes to prevent cables from getting cut.
 
  #26  
Old 11-25-14, 08:59 AM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
The only concern is that if your mobile home has metal studs or metal siding you're running cable through there has to be rubber/plastic grommits in the holes to prevent cables from getting cut.
Noted.

It has 2x4 wood studs. It used to have metal siding, but it was removed and replaced with wood sheathing and vinyl siding.

I am ripping all the interior walls to replace insulation and drywall in place of paneling so I will have full access to all wiring accept where it is run through the ceiling. All existing recepticals are currently screwed to the paneling, not studs. One of the reasons I decided to go ahead and replace the existing wiring is because it will already be exposed. Better to do it all at once, than to rip new wall out when problems do arise.
 
  #27  
Old 11-25-14, 12:55 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,289
Received 43 Votes on 35 Posts
Propery deed states it was put in place in 1976
Was the mobile new in 1979? I am not sure in what year aluminum wiring was prohibited in mobile homes, but aluminum wiring was still being used in new houses after the mobile industry had to stop using it. Regardless, if it has aluminum wiring, that in itself is a good reason to replace it.

All existing recepticals are currently screwed to the paneling, not studs
Hopefully the receptacles are installed in boxes.
 
  #28  
Old 11-25-14, 01:43 PM
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 15
Received 0 Votes on 0 Posts
Was the mobile new in 1979? I am not sure in what year aluminum wiring was prohibited in mobile homes, but aluminum wiring was still being used in new houses after the mobile industry had to stop using it. Regardless, if it has aluminum wiring, that in itself is a good reason to replace it.
I don't know the actual age of the mobile home. Only that the property deed states it was added in 1976. The existing wiring is copper.

Hopefully the receptacles are installed in boxes.
LOL, yes they are installed in boxes. I don't know how much code has change for mobile homes over the years, but I can definately see the need for it in the first place.
 
  #29  
Old 11-25-14, 03:14 PM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
Some of the earlier mobiles from like the 60s I don't think had a building code at all -- they were built more like travel trailers. They have these snap-in sort of receptacles and switches that don't have junction boxes. They're a real pain in the butt to deal with. Thankfully you don't have that problem.
 
  #30  
Old 11-25-14, 04:04 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,997
Received 40 Votes on 35 Posts
Manufactured housing is built using a different standard than the NEC.
 
  #31  
Old 11-25-14, 07:12 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 13,057
Received 73 Votes on 65 Posts
Mobile Homes, Manufactured Homes, and Mobile Home Parks Art 550 NEC

Also you can only have one feed to a building. Adding another 100 amp panel is not an option.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: