49
Marvair Wall Mount Heat Pump I&O Manual
11/2021 New
Mechanical Heat Lockout ODT (Electric Heat ONLY
While the system is operating in “Mechanical Heating Mode”. Activate Mechanical Heat Lockout
(ODT).
* Your unit may be configured with an outdoor thermostat configured as “Auxiliary Heat”,
“Mechanical Heat Lockout”, or No outdoor thermostat. *
Do Not change the temperature setpoint on the thermostat / control. Simply adjust the ODT setpoint to
approximately four degrees below the current outdoor temperature. After the short delay, the unit will
activate Mechanical Heat Lockout, start heating with Only Electric heat. Notice: system did not turn
off. “Mechanical Heat” turned Off and “Electric Heat” turned On.
Note: The “S” Circuit (Marvair
Heat Pump control board) must be set to “Yes”, to allow Mechanical Heat Lockout.
Is the indoor blower motor (IBM) On? .............................................................................
❒
Yes
❒
No
Is the Compressor Off? .....................................................................................................
❒
Yes
❒
No
Is the Condenser Fan (CFM) Off? ....................................................................................
❒
Yes
❒
No
Is the Heater On? (Clamp an AmpProbe on one leg of the heater contactor to verify) ....
❒
Yes
❒
No
Heating (Check and Record Readings)
After about 10 minutes of operating in the heating mode, check and record the following data points.
Inside Temperature (IAT)
ºF
Outside Temperature (OAT)
ºF
Return Air Temperature (RAT) db (Should be same temp as IAT)
ºF
Return Air Temperature (RAT) wb (used to calculate RH% of Return Air)
ºF
Supply Air Temperature (SAT) db (Acceptable Range 15º - 20º below RAT)
ºF
Return Air Temperature (SAT) wb (used to calculate RH% of Supply Air)
ºF
Heater Contactor Amps (HCAL1)
ºF
Heater Contactor Amps (HCAL2)
ºF
Heater Contactor Amps (HCAL3)
ºF
Heater Circuit Volts (L1&L2)
ºF
Heater Circuit Volts (L1&L3)
ºF
Heater Circuit Volts (L2&L3)
ºF
Calculate Heater kW
Single Phase Units
Heater kW = (HCAL1*L1&L2)/1000 = _______________kW.
Example: HCAL1 * L1&L2
1000
Measured Voltage: L1&L2 = 241 Volts
Measured Amperage: L1 = 20.7 Amps
4988.7 / 1000 = 4.99kW (5kW)
