Customer calls and needs a dryer circuit ran. Well I quote a price (roundabout) and schedule the job. I get to the house and find out it is a mobile home with only a 40amp feeder to the 100 amp panel, typical. There is a window ac, refridge, and other basic loads. I did install the dryer circuit and explained to the owner the limited ampacity of her service and told her what may happen if her electrical consumption exceeds her 40 amp feeder. So she knows the situation, the main feeder breaker may trip. Are there some here that would refuse the job based on her limited service? She had already purchased the appliance. So far, no call that the main is tripping when everything is on at the same time and she does know about the possibility. Any input on how any of you would have handled this?
How would you have handled this?
- Thread starter BruceH
- Start date
- Status
GG
Senior Member
- Location
- Ft.Worth, T.X.
Re: How would you have handled this?
Did you try to sell her on installing a 100A feeder? I think if you have a 40A feeder it is only a matter of time before the 40A breaker trips from what you described. I personally would not have hooked up the dryer until the undersized feeder was increased to 100amps. I always think of the worst case scenario, now if the house catches fire due to the dryer circuit overloading the service the ins. company is going to ask well who installed the dryer,and then she will lay all the blame on you. Better to do the job right the first time, and sleep better at night not having to worry. JMO.
[ August 17, 2005, 10:51 PM: Message edited by: GG ]
Did you try to sell her on installing a 100A feeder? I think if you have a 40A feeder it is only a matter of time before the 40A breaker trips from what you described. I personally would not have hooked up the dryer until the undersized feeder was increased to 100amps. I always think of the worst case scenario, now if the house catches fire due to the dryer circuit overloading the service the ins. company is going to ask well who installed the dryer,and then she will lay all the blame on you. Better to do the job right the first time, and sleep better at night not having to worry. JMO.
[ August 17, 2005, 10:51 PM: Message edited by: GG ]
Re: How would you have handled this?
I went on one of those calls the other day...this was for an electric stove - sitting right in the kitchen to replace a gas unit. When I told them it would be 3k, they were very surprised - to say the least. I told them they needed a new service(60A existing on a 2-family).
I wouldn't hook it up just for the sake of hooking it up. Either I do it soup to nuts or I don't do it.
I won't be holding my breathe waiting for them to call me back.
I imagine you will be getting a call some time this winter...when the days are really short and the temp is low.
[ August 17, 2005, 10:52 PM: Message edited by: celtic ]
I went on one of those calls the other day...this was for an electric stove - sitting right in the kitchen to replace a gas unit. When I told them it would be 3k, they were very surprised - to say the least. I told them they needed a new service(60A existing on a 2-family).
I wouldn't hook it up just for the sake of hooking it up. Either I do it soup to nuts or I don't do it.
I won't be holding my breathe waiting for them to call me back.
I imagine you will be getting a call some time this winter...when the days are really short and the temp is low.
[ August 17, 2005, 10:52 PM: Message edited by: celtic ]
Re: How would you have handled this?
Thanks for the replies. I did try to sell her on the service upgrade and noted everything on the invoice. The mobile home park has authority on what lot gets upgraded. I will be contacting her soon on a follow up to again advise her on her situation and again try to set up the upgrade. I do feel that I goofed on this one but if I push the upgrade and get it done I will sleep better. The main feeder breaker is outside and is a fairly modern Sq D QO and the panel inside is a mlo.
Thanks for the replies. I did try to sell her on the service upgrade and noted everything on the invoice. The mobile home park has authority on what lot gets upgraded. I will be contacting her soon on a follow up to again advise her on her situation and again try to set up the upgrade. I do feel that I goofed on this one but if I push the upgrade and get it done I will sleep better. The main feeder breaker is outside and is a fairly modern Sq D QO and the panel inside is a mlo.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: How would you have handled this?
My initial reaction was that Bruce handled this situation in a reasonable manner, and that Celtic's view of the situation was equally reasonable. Then I put myself in the role of a design engineer who has been asked to design a modification to the mobile home. Engineers don't often get hired to do this kind of job, but let's talk about it in terms of a formal design project.
What you are adding is a permanent load ? a dryer receptacle. When I add a new load to an existing facility, I must be able to prove (to the satisfaction of the AHJ) that this new load will not overload any branch circuit, feeder, service conductor, or panel. I have two options. I can perform a service calculation, as though this was a brand new building being designed. The other option is to take load readings over a 30 day period. I take the maximum load observed in that time period (in units of VA or amps), add 25%, and then add the new load. If nothing is overloaded, I can seal and issue the plans. If anything is overloaded, then I must stop and get a resolution, before issuing the design.
So my present inclination is to follow neither Bruce's nor Celtic's path. I would take the additional step of verifying that adding the load will not cause any problems. If I can prove there are no problems, then I follow Bruce. If there are problems, then I follow Celtic.
My initial reaction was that Bruce handled this situation in a reasonable manner, and that Celtic's view of the situation was equally reasonable. Then I put myself in the role of a design engineer who has been asked to design a modification to the mobile home. Engineers don't often get hired to do this kind of job, but let's talk about it in terms of a formal design project.
What you are adding is a permanent load ? a dryer receptacle. When I add a new load to an existing facility, I must be able to prove (to the satisfaction of the AHJ) that this new load will not overload any branch circuit, feeder, service conductor, or panel. I have two options. I can perform a service calculation, as though this was a brand new building being designed. The other option is to take load readings over a 30 day period. I take the maximum load observed in that time period (in units of VA or amps), add 25%, and then add the new load. If nothing is overloaded, I can seal and issue the plans. If anything is overloaded, then I must stop and get a resolution, before issuing the design.
So my present inclination is to follow neither Bruce's nor Celtic's path. I would take the additional step of verifying that adding the load will not cause any problems. If I can prove there are no problems, then I follow Bruce. If there are problems, then I follow Celtic.
growler
Senior Member
- Location
- Atlanta,GA
Re: How would you have handled this?
The problem may be that the mobile home park does not allow washers and dryers because the service was not designed for it. I had an apartment complex that when the weather started to turned cool there were breakers tripping all over. The real problem was tenants using space heaters to save money on the gas bill. They had gas heat with no provisions for electric heat. When doing anything in a mobile home park, it's wise to check with management. They may provide a laundry facility in liew of individual washers & dryers.
The problem may be that the mobile home park does not allow washers and dryers because the service was not designed for it. I had an apartment complex that when the weather started to turned cool there were breakers tripping all over. The real problem was tenants using space heaters to save money on the gas bill. They had gas heat with no provisions for electric heat. When doing anything in a mobile home park, it's wise to check with management. They may provide a laundry facility in liew of individual washers & dryers.
Re: How would you have handled this?
Gentleman, I certainly appreciate all the input. The washers and dryers are allowed and most of the mobiles have them. Being cautious with my wording I called the customer again today to express my concerns with colder weather coming and the possibility of overloading the main feeder breaker. She has been thinking about the same thing herself since I already explained it to her a few times and noted it on the invoice. Well, I'm thanking my lucky stars because it looks like she wants it done for sure before Autumn arrives. The pedestal service ampacity is adequate and the park management doesn't have a problem with it and just needs to check my license, insurance, etc. I will be replacing the mlo panel and installing arc faults, smoke detectors and new gfci's where required. Thank god there's no aluminum to deal with ! I'll certainly sleep better and I'm sure the customer will also. I won't make a mistake like this one again as I got lucky this time. Next time I will be thinking all or nothing, and won't be rolling any dice, it's just not worth the risk, even if the service would have handled it. Again, thanks for the input.
Gentleman, I certainly appreciate all the input. The washers and dryers are allowed and most of the mobiles have them. Being cautious with my wording I called the customer again today to express my concerns with colder weather coming and the possibility of overloading the main feeder breaker. She has been thinking about the same thing herself since I already explained it to her a few times and noted it on the invoice. Well, I'm thanking my lucky stars because it looks like she wants it done for sure before Autumn arrives. The pedestal service ampacity is adequate and the park management doesn't have a problem with it and just needs to check my license, insurance, etc. I will be replacing the mlo panel and installing arc faults, smoke detectors and new gfci's where required. Thank god there's no aluminum to deal with ! I'll certainly sleep better and I'm sure the customer will also. I won't make a mistake like this one again as I got lucky this time. Next time I will be thinking all or nothing, and won't be rolling any dice, it's just not worth the risk, even if the service would have handled it. Again, thanks for the input.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: How would you have handled this?
Better rethink that MLO
Better rethink that MLO
mdshunk
Senior Member
- Location
- Right here.
Re: How would you have handled this?
Bruce... I'm not ashamed to admit that in the past I've done similar things that bothered me for days and weeks. At least twice I revisited two installations to do additional work for free just to clear my conscience. Not a recommended "how to build a successful business" method, but it helped me sleep.
Bruce... I'm not ashamed to admit that in the past I've done similar things that bothered me for days and weeks. At least twice I revisited two installations to do additional work for free just to clear my conscience. Not a recommended "how to build a successful business" method, but it helped me sleep.
Re: How would you have handled this?
Thanks Md, damn you're fast jimwalker, I just realized my wording mistake. There is a main lug only now, I will be installing a SqD QO 100 amp main breaker panel. As of now, it violates the 6 disconnect rule. I figured I'd better come back and post a correction before someone caught me on that, too late. You guy's are too sharp to let that one slip by.
Thanks Md, damn you're fast jimwalker, I just realized my wording mistake. There is a main lug only now, I will be installing a SqD QO 100 amp main breaker panel. As of now, it violates the 6 disconnect rule. I figured I'd better come back and post a correction before someone caught me on that, too late. You guy's are too sharp to let that one slip by.
busman
Senior Member
- Location
- Northern Virginia
- Occupation
- Master Electrician / Electrical Engineer
- Status