Electronic Control Board Mode Of Operation - Industrial Climate Engineering MiniPac ECUA06ACA A2 Series Operation And Installation Manual

Evaporator Blower Motor Capacitor (N3 series only)
• Start/run capacitor for PSC evaporator motor.
• 3 µfd @ 440 VAC.
• Provides starting torque and improves operating efficiency.
• Built into the 115V motor, separate on 230V motor.
Condenser Blower Motor Capacitor
• Start/run capacitor for PSC (permanent split capacitor) condenser motor.
• Provides starting torque and improves operating efficiency.
1.4

Electronic Control Board Mode of Operation

Normal
24 VAC power must be continuously applied to "R" and "C". Upon a call for cooling "Y" and with
the high pressure switch (HPS) closed, the compressor will be energized. (Note: See the delay on
make feature.) The compressor will remain energized during the 3 minute timed low pressure by-pass
cycle. If the low pressure switch (LPS) is open after the 3 minute by-pass cycle, the compressor will
de-energize.
Lock-out
If either of the fault conditions (LPS or HPS) occurs twice, the control board will enter into and indicate
the lockout mode. In the lockout mode, the compressor is turned off. If there is a call for indoor air
flow "G", the blower remains energized, the alarm output is energized and the status led will blink
to indicate which fault has occurred. When the lockout condition is cleared, the unit will reset if the
demand for the thermostat is removed or when the power is reset. With the control board, the user can
now have either normally closed or normally open contacts by moving a wire on the control board.
The ComPac
®
Delay on Break
If the compressor is de-energized due to a loss of a cooling "Y" call or the first fault, the unit re-start
will be delayed 3 minutes from the time the contactor is de-energized. (Note: There is no delay on
break if the lockout condition is reset.)
Delay on Make
On initial power up only, the unit will wait 0.03 to 10 minutes from the cooling "Y" call before al-
lowing the contactor to energize. The delay can be adjusted by the DOM wheel on the board. Factory
recommended wait is 3 minutes.
Low Pressure By-Pass Time
When starting, the low pressure switch (LPS) fault condition will be by-passed for 3 minutes before
the contactor is de-energized.
Post Purge
Upon a call for indoor airflow "G" the blower will energize immediately. When in the cooling mode,
the blower will remain energized for 10 to 90 seconds (adjustable) after the compressor has been
de-energized. The time period can be changed by fan purge wheel on the board. Factory setting is 90
seconds.
air conditioners are factory wired to be normally open.
7
ECUA06 7/2014 new