MULTI−FUNCTION TEST PINS (E33)
Placing the jumper on the field test pins (E33) using a specific sequence allows the technician to:
S S S S
Clear short cycle lockout
Clear five−strike fault lockout
Cycle the unit in and out of defrost mode
Manually place the unit in defrost mode to clear the coil
WhenY1 is energized and 24V power is being applied to the heat pump control (A175), a test cycle can be initiated by placing a jumper on the heat pump control’s TEST pins for 2 to 5 seconds. If the jumper remains on the TEST pins (E33) for longer than five seconds, the heat pump control will ignore the jumpered TEST pins and revert to normal operation.
The heat pump control will initiate one test event each time a jumper is placed on the TEST pins. For each TEST the jumper must be removed for at least one second and then reapplied.
Y1 Active
Place a jumper on TEST pins for longer than one second but less than two seconds.
Clears any short cycle lockout and five strike fault lockout function, if applicable. No other functions will be executed and unit will continue in the mode it was operating.
Place a jumper on TEST pins for more than two seconds.
Clears any short cycle lockout and five strike fault lockout function, if applicable.
ACTIVE | O Line Status | INACTIVE |
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If in COOLING Mode
If in DEFROST Mode
If in HEATING Mode
No further test mode operation will be executed until the jumper is removed from the TEST pins and reapplied.
The unit will terminate defrost and enter HEAT MODE uncalibrated with defrost timer set for a maximum 34 minute test.
If no ambient or coil sensor fault ex- ist, unit will go into DEFROST MODE.
If ambient or coil faults exist (open or shorted), unit will remain in HEAT MODE.
NOTE eat pump control c annot be force into defrost mode when the ambient temperature input from the RT13 sensor is above 65ºF (18ºC).
NOTEault is detected, the board will not execute the TEST mode.
If jumper on TEST pins remains in place for more than five seconds.
The unit will return to HEAT MODE un−calibrated with defrost timer set for 34 minutes.
If jumper on TEST pins is removed before a maximum of five seconds.
The unit will remain in DEFROST MODE until termination on time or
temperature.
Figure 27. Test Pin (E33) Functions
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XP17 SERIES
