Interesting issue with Basement Heatpump

[navychaps]

Perhaps someone can enlighten me to what is happening.

When in "electric heat" mode, and the second compressor starts I get an initial amperage of 21/22 amps draw which then slowly creeps up to 31 amps where the power management system shuts down the water heater, second compressoor and slows fan speed. the unit then continues heating on one compressor. This does NOT happen in A/C mode with both compressors running.

2003 Adventurer 33V

[DancinCampers]

I would suggest something is miswired.

This is the way it should act in the cooling mode, not heating mode.

[BFlinn181]

I've never owned a heat pump, but it is my understanding that when the temperature is too cold to efficiently get heat from outside air, the compressor shuts down and all heat is provided by electric heat elements in duct work, only the fan runs, not compressor.

[Mr_D]

Originally Posted by BFlinn181

I've never owned a heat pump, but it is my understanding that when the temperature is too cold to efficiently get heat from outside air, the compressor shuts down and all heat is provided by electric heat elements in duct work, only the fan runs, not compressor.

Not sure about the basement air units but in our MH, if the outside temps get too low it automatically shuts the heat pumps off and switches to the furnace.
Our stiock house heat pump does the same thing.

[grtharris]

Are the outside coils icing up? If they are this will cause the head pressure to increase and increase the amp draw.

[navychaps]

Originally Posted by DancinCampers

I would suggest something is miswired.

This is the way it should act in the cooling mode, not heating mode.

Originally Posted by BFlinn181

I've never owned a heat pump, but it is my understanding that when the temperature is too cold to efficiently get heat from outside air, the compressor shuts down and all heat is provided by electric heat elements in duct work, only the fan runs, not compressor.

Originally Posted by Mr_D

Not sure about the basement air units but in our MH, if the outside temps get too low it automatically shuts the heat pumps off and switches to the furnace.
Our stiock house heat pump does the same thing.

Originally Posted by grtharris

Are the outside coils icing up? If they are this will cause the head pressure to increase and increase the amp draw.

Dancin--I've never had work done on the unit and it worked fine previously--Thanks

BFlinn181/Mr_D-- No heating elements an my basement unit and outside air temp is well above freezing--Thanks

grtharris-- I will check that and get back with you....

[Springer45]

The initial shed is due to being over 30amps. This is why the water pump turns off. Depending on what else is running it sounds like with the Heat pump on with more than a 3 degeree difference between demand and actual temperatures you are exceeding 30 amps. The EMS will shed teh second compressor and reduce fan speed at that time. If you want the heat pump to work with both compressors you will need to reduce the other appliance load. This only happens on shore power since the second compressor is wired outside the ems when running on generator

[navychaps]

Originally Posted by Springer45

The initial shed is due to being over 30amps. This is why the water pump turns off. Depending on what else is running it sounds like with the Heat pump on with more than a 3 degeree difference between demand and actual temperatures you are exceeding 30 amps. The EMS will shed teh second compressor and reduce fan speed at that time. If you want the heat pump to work with both compressors you will need to reduce the other appliance load. This only happens on shore power since the second compressor is wired outside the ems when running on generator

Springer, thanks but the issue is that it should only draw 21/22 amps with both compressors running. Even if I turn every other item off in the MH it will still creep up to 31 amps and shed the second compressor. Interesting thing is, when in cooling mode with both compressors running it draws 21/22 amps and stays there...

[Springer45]

Intersting. I understnad your explination better now. I assume you have cyceld the A/C compressor 1 switch off with compressor 2 also off and the EMS readout goes down to the normal 1 or 2 amp draw?

[Cat]

Sounds like the freon reversing valve is not allowing the freon to reverse when in heat and blocks off the freon instead,which causes high head pressure which equals more amperage. The valve is electrically controlled but must physically move to change the direction of the freon.

[navychaps]

Originally Posted by Cat

Sounds like the freon reversing valve is not allowing the freon to reverse when in heat and blocks off the freon instead,which causes high head pressure which equals more amperage. The valve is electrically controlled but must physically move to change the direction of the freon.

Cat, I was thinking that may be the problem....I wonder if there is an "easy" way to access the valve and possibly lubricate/repair the valve.....

[harv12]

What is the indoor/outdoor temperature when this is happening? With heat pumps if it's too warm either inside or outside there may not be enough air flow to cool the hot refrigerant going through the indoor coil. That maybe why you're seeing the amperage "creep up". Reversing valves are typically in "heating" mode when they're not energized because most manufacturers assume the unit will do more cooling than heating and that keeps the valve moving so it doesn't stay in the same position too long and have sticking issues.
If one were normally in the "cooling" position and not functioning properly and refrigerant was short cycling I wouldn't think you'd see a 10 amp rise. You'd probably notice that your discharge air temperature was much cooler.
Reversing valves use an electronic coil to activate the "slide" mechanism and those do sometimes fail or can have a corrosion issue. They're usually not something that would be "owner" serviceable. I'm not sure how accessible they are on the basement air systems, but if you can, look at the electric coil on the valve for loose or corroded wires {there will only be two wires going to the valve}. If it's possible to safely access the valve while the compressor is running you can feel the copper line that goes to the indoor coil and it would hot {very} while the valve was in the heating mode.
Best of luck and let us know what you find.

[RonP]

navychaps, My basement air has been operating with amp readings as you indicated for over a year. It does appear to be more of a problem when I turn on the heat pump when temps are in the 50 degree range.
Perhaps there is not enough cold air to keep the head pressure down.
I do not recall this being a problem prior to a year or so ago so I would
be very interested in any thoughts as to cause.

[navychaps]

Originally Posted by harv12

What is the indoor/outdoor temperature when this is happening? With heat pumps if it's too warm either inside or outside there may not be enough air flow to cool the hot refrigerant going through the indoor coil. That maybe why you're seeing the amperage "creep up". Reversing valves are typically in "heating" mode when they're not energized because most manufacturers assume the unit will do more cooling than heating and that keeps the valve moving so it doesn't stay in the same position too long and have sticking issues.
If one were normally in the "cooling" position and not functioning properly and refrigerant was short cycling I wouldn't think you'd see a 10 amp rise. You'd probably notice that your discharge air temperature was much cooler.
Reversing valves use an electronic coil to activate the "slide" mechanism and those do sometimes fail or can have a corrosion issue. They're usually not something that would be "owner" serviceable. I'm not sure how accessible they are on the basement air systems, but if you can, look at the electric coil on the valve for loose or corroded wires {there will only be two wires going to the valve}. If it's possible to safely access the valve while the compressor is running you can feel the copper line that goes to the indoor coil and it would hot {very} while the valve was in the heating mode.
Best of luck and let us know what you find.

Originally Posted by RonP

navychaps, My basement air has been operating with amp readings as you indicated for over a year. It does appear to be more of a problem when I turn on the heat pump when temps are in the 50 degree range.
Perhaps there is not enough cold air to keep the head pressure down.
I do not recall this being a problem prior to a year or so ago so I would
be very interested in any thoughts as to cause.

Harv, This morning it was about 55 degrees outside and 68 inside when I turned it on to bring it to 75. After about 15 minutes the system hit 31 amps.

Ron, You may be correct but the system has never performed this way previously when I used it in similar temps.

I'll let you know more as I research the issue. Not sure if I will have to pull the unit to get access so it may be a few days before I attack the issue.

Thanks for the great info and suggestions.

[DancinCampers]

navychaps

Is your coach wired for 50 amps?

You may want to check your indoor evap coil for obstructions, as low airflow will cause the head pressure to rise in heat mode.

[navychaps]

Originally Posted by DancinCampers

navychaps

Is your coach wired for 50 amps?

You may want to check your indoor evap coil for obstructions, as low airflow will cause the head pressure to rise in heat mode.

Dancin' It's a 30 amp coach. I will check the evap coil! Thanks.