York Package Heat Pumps: BHZ

Re: Outdoor Fan Not Running

• The BHZ Package Heat Pump uses a 1/4HP, 850 RPM, Standard PSC Condenser Fan Motor.
• There are two control boards in this unit, a fan timer board and a defrost board.
• On the BHZ package units the defrost board controls the compressor contactor and condenser fan.

CHECKOUT:

1. Check Power

• Disconnect power to O/D unit by pulling disconnect or turning off breaker.
• CAUTION! There is typically more than one power feed to package heat pumps.
  • Open the blower door and lower the electrical compartment cover. 
  • Use a multi-meter to check resistance across each fuse.
  • Inspect for burnt wiring or burnt contactor contacts.
• Re-apply power to the unit and set the thermostat to call for heat or cool.
• Check for 24VAC between "R" and "C" on the Fan Timer control board.
  • No Power = No High Voltage Power, Blown Low Voltage Fuse or Bad Transformer
• Check for 24VAC between "Y" and "C" on the Fan Timer control board.
  • No Power = No Call from Thermostat ⇒ Check Thermostat
  • Power Present ⇒ Compressor and Condenser Fan should start within 5 minutes.
    • No Compressor or Condenser Fan Operation after 5 minutes → Step 3. Check Safety Circuit
    • Compressor but No Condenser Fan → Step 2. Check Motor & Capacitor

2. Check Motor & Capacitor

• Check Motor Power
  • Check for 230V between Black "Common" wire and Purple or Yellow "Run" wire on the capacitor.
    • No Power = Defrost Mode or Bad Defrost Control Board
• Check Capacitor
  • Turn off all power to the unit.
  • Remove capacitor wires (short with a screwdriver or pliers before touching)
  • Move Multi-Meter leads to COM and MFD.
  • Set Meter to 200 MFD.
  • Place one lead on each side of the capacitor. 
  • Confirm MFD reading with capacitor rating.
    • Less than 80% of rating = Bad Capacitor
  • SWITCH METER LEADS BACK TO COM AND V BEFORE PROCEEDING!

3. Check Safety Circuit

• With wires still plugged-in, check for 24VAC between "C" and both "Pressure Switch" terminals of the defrost control board.
  • Power on both terminals = Control Likely in Lockout ⇒ Reset power and retry
  • Power on one terminal but not the other = Open Hi or Lo Pressure Switch ⇒ Check Refrigerant Pressure