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Heat pump thermostat wiring for split systems


24 volt wiring for a split system heat pump

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New LG mini split installation getting error CH05


I believe the wiring may be incorrect. Here arethe fault codes.

05

Comms Error, check your wiring, remove external pumps. Split/Multi - check volts from terminal N to 3 = 0 - 65 Vdc, Multi V - 4 Vdc terminals 3 and 4

5

Comms Error, check your wiring, remove external pumps. Split/Multi - check volts from terminal N to 3 = 0 - 65 Vdc, Multi V - 4 Vdc terminals 3 and 4
Hope this helps

Bob

Aug 08, 2014 | LG LA120HYV Art Cool Premier 120HYV Ultra...

1 Answer

a/c on 3 ton 13 seer ruud heat pump not cooling


you have condenser issue. check at outside unit for 240 volts to contactor and 24 volts to contactor coil.

May 11, 2013 | Ruud 3 Ton Split System Heat Pump

1 Answer

Fedder Heat Pump not Running


you can check your heat pump on the outside by turning off the power and listening to see if it makes a whoosh sound. and then turn it back on you should hear it kick in. Is the outside unit running? Sounds like an electrical problem maybe in the breaker or the contactor on the inside of the unit. This is where the 24 volts from the thermostat call to the 240 volts to kick on the condenser fan and compressor. Be real careful in messing with this because of the high voltage.

Jul 09, 2010 | Fedders C36ACD1VF Split System Air...

1 Answer

Gold Star mini split heat pump 24,000 btu. Changed indooe as we as outdoor boards and still goes in cooling mode only. Reset button on outdoor board calls in heat but not by inside hand set. Len Cabana Techno Refrig. Inc. PS: Sometimes indoor green light flashes five times. Close power breaker and try again with inside hand set. Still no heat or fan on.


On a heat pump the difference from heat to cool is the reversing valve.
In cooling or heating the Y1 terminal will always be energized, this is the contactor.
Depending on brand the reversing valve will either be energized in Heat or Cool. At the outdoor unit check to see if the reversing valve is getting 24 volts in cool, if not check to see if it is getting 24 volts in heating. The easiest way to check if the reversing valve is shifting, is to feel the big copper tube, (it is not the suction line on a heat pump) this is a refrigerant vapor line. It will be cold in cooling and hot in heating.
Check your thermostat installation instructions and heat pump installation instructions to determine the proper terminal designations for your heat pump and thermostat. There are some brands out there that use the B terminal as common to the 24 volt circuit, so you have to check the wiring and make sure this is not common.
If it is energized in Cool then the Y1 and O terminal will be energized. You will have 24 volts from common usually the C terminal to Y1 and O.
If it’s energized in Heat then the Y1 and B terminal should be energized. You will have 24 volts from common usually the C terminal to Y1 and B.
If you get heat when you’re calling for cooling or vice versa then switch the wire between the B and O terminals.

Feb 01, 2010 | LG LS-K2430HL Heat Cool Mini Split Air...

1 Answer

trying to figure out thermostat wiring diagham on a split system


Typical Thermostat Wiring for 4 or 5 wire Heat/Cool Thermostat (not heat pumps)
4 Wire Termostat
R = Red One Side of 24 volt Transformer
G = Green Blower
Y = Yellow Cool
W = White Heat
5 Wire Thermostat
with one transformer for both units
Rc One Side of 24 volt Transformer
Rh Jumper Rc to Rh
G = Green Blower
Y = Yellow Cool
W = White Heat
5 Wire Thermostat
With 2 transformers one for indoor unit
And one for outdoor unit
Rc = Red One Side of (outside) 24 volt (outside transformer)
G = Green Blower (outside transformer)
Y = Yellow Cool (outside transformer)
Rh = Blue One side of (inside) 24 volt (inside transformer)
W = White Heat (inside transformer)
COOLING ONLY Thermostat
R = Red One Side of 24 volt Transformer
G = Green Blower
Y = Yellow Cool
HEATING ONLY
R or Rh One Side of 24 volt Transformer
W = White Heat

Jan 05, 2010 | Heating & Cooling

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