surge fried the frig

[rickl]

well i stopped by today to look things over, everything look ok to me. voltage at frig 122 volt when heat pumps starts the voltage drops to 117 for 1 or 2 seconds then returns to normal. i think will have them replace the board and see what happens,
thanks for the help

 

[charlie tuna]

remember that the new high efficiency a/c units now use scroll compressors. these new compressors are basically, a freon pump. the old compressors would start with very little head pressure and slowly increase meaning it was not starting under much load. the scroll units start under full load which causes an inrush current that we are not used to seeing. your installation with #6 wire is plenty--it's just something people have to live with. and i agree that equipment boards are mainly made in china and who knows where, and the standard cause by the manufacturer's service tech is "surge"!!!

 

[A/A Fuel GTX]

3500 sf house, 320 amp underground service, 2 - 200 amp qo panels

Did your load calcs really justify a 320A service for a house of this size? I'm not criticizing you but it seems like a little overkill for a 3500 sf house.

 

[winnie]

(The design was laid out incorrectly.) that statement really pissed me off how can you make that assessment sitting in front of your computer 1000 miles away.

Clearly you should have brought in a separate 480/277 service for the heat pump.

*grin*

-Jon

 

[LarryFine]

Did your load calcs really justify a 320A service for a house of this size? I'm not criticizing you but it seems like a little overkill for a 3500 sf house.

It depends on the load and load calc, as you said. An all-electric house with resistance heating can require twice the service as one the same size with gas heat and appliances.

 

[A/A Fuel GTX]

Yeah, maybe the heat pump has auxilliary heat strips and maybe there are supplemental base board heaters or maybe even an electric boiler for in floor heat. I'd like to know the specs. If it's just a large heat pump and a normal 3500 sf home, I'd think a 200A service would have been adequate.

 

[rickl]

Quote:
Originally Posted by m73214
Did your load calcs really justify a 320A service for a house of this size? I'm not criticizing you but it seems like a little overkill for a 3500 sf house.

no, the homeowner decided he wanted the 320 meterbase so i did no load calc. generally houses i wire that are over 3000 sf (all electric) will get a 320 service unless the h/o doesn't want it which is his call. maybe an overkill, but 50 years ago people would tell you a 200 amp in a 1500 sf home was an overkill, all i know is that homeowners have a habit of adding thing at the last minute. and if you were wiring my 3500 sf house and i asked you to wire a hot tub i just purchased & your response was, ok but we will have to upgrade your service first, you wouldn't be working for me any longer.

house specs: all electric
18k heat
3 hot water tanks (2 in series)
110 can lights (max wattage 120)
double oven
cooktop
2 dryers 2 washers( i don't no why but thats what they wanted)
3 garage door openers
100 sf of tile floor heat
2 big freezers in the garage
rv hookup ( 50 amp 240 volt)

i probably could use the optional load calc and maybe be under 200 amps, but why not do the job right the first time. 320 service costs about $ 200 more in materials, plus he has the option to add loads ( hot tub, shop,etc) with a 200 amp service ho gets no space for future loads. plus i don't want to get a call on thanksgiving day from the ho telling me he has a house full of people & his main breaker keeps tripping.

 

[ItsHot]

refrigerators

refrigerators

Refrigerators run 24 / 7 and use to last for 25+years. I was on a small job the other day and the HO had a repairman working on the refrigerator. The "board was bad"! This appliance was only 2 years old!

 

[brian john]

My mother owned one washer, no dryer, same refrig as long as I can remember and a furnace that operated for ever. In my house, in 16 years I am on my 3rd set of washer dryers, second frig freezer (first set were Sub Zero). And the high efficiency furnace has cost me way more money in service than I have saved.

 

[A/A Fuel GTX]

Quote:
house specs: all electric
18k heat
3 hot water tanks (2 in series)
110 can lights (max wattage 120)
double oven
cooktop
2 dryers 2 washers( i don't no why but thats what they wanted)
3 garage door openers
100 sf of tile floor heat
2 big freezers in the garage
rv hookup ( 50 amp 240 volt)

.

Wow....How did you get all that in a 3500sf house After seeing the specs, I would have done the same thing. You've got a 75A heat load alone. I just bid a 4500sf house and figured 80 cans and thought I was a bit extreme. Now I feel like I held back .

 

[jem.nola]

The house and ho sounds doomed from the beginning.

 

[hockeyoligist2]

For some reason flicker seems to bother women more that men (based upon personal experience).

Yea, I have noticed that too.

 

[jacobsond]

As a low volt guy plus electronics service man and appliance service man I can tell you the service man could NOT tell you it was a power surge unless there were burned spots on the board. Electronic circits fail. The reason is usually not found unless there was a Mechanical problem that caused a burnout on the control board. Power inturuption and a possible spike at turn on may cause a board to fail but a power reduction down to even 110V would not likley cause the failure. Boards fail customers want a cause and dont want to hear " the board just failed". So " it must have been a spike" has been born. Just like any electrical problem is always "a short" when many times that is far from the truth.

 

[ELA]

I can not imagine a major manufacturer of an appliance building a unit incorporating an electronics board and not designing in surge protection as well.
If the board was supposed to be destroyed by a surge then I would expect the built-in surge protection to show signs of being over loaded.

If there is no built-in surge protection then the manufacturer is at fault.

If there is built-in surge protection (and this is not weather related) then it gets a little more difficult to determine fault.

 

[K8MHZ]

Be advised that in any AC inductive motor circuit low supply voltage will cause the motor to overheat and produce an excessive current draw. This is due to the lack of reverse EMF in the motor from the rotor not spinning at full speed. (This is why freq drives are required to control the speed of AC inductive motors) Low voltage may cause not only a motor failure but failure of anything in the circuit that is subject to the higher current draw due to the motor not having sufficient voltage. I don't know if that is the cause in this particular case, but it is a possibility.