From inside (document excerpt):
25HCB5 Comfortt Series Heat Pump with Puronr Refrigerant 1 1/2 To 5 Nominal Tons Wiring Diagrams CONNECTION DIAGRAM THIS DEFROST CONTROL BOARD CONTAINS A FIVE MINUTE SHORT CYCLE PROTECTOR.
A FIVE MINUTE DELAY WILL OCCUR BETWEEN COMPRESSOR OFF/ON CYCLES. NOTE C Y O W2 R E L W3 G C Y O W2 R E L INDOOR UNIT TERMINAL BLOCK G INDOOR THERMOSTAT (NOTE #5) NOTES: COMPRESSOR AND FAN MOTOR FURNISHED WITH INHERENT THERMAL PROTECTION. TO BE WIRED IN ACCORDANCE WITH NATIONAL ELECTRIC CODE (N.E.C.) AND LOCAL CODES. N.E.C. CLASS 2, 24 V CIRCUIT, MIN. 40 VA REQUIRED, 60VA ON UNITS INSTALLED WITH LLS. USE COPPER CONDUCTORS ONLY FROM DISCONNECT TO UNIT. MUST USE THERMOSTAT AND SUB-BASE AS STATED IN PRE-SALE LITERATURE. IF INDOOR SECTION HAS A TRANSFORMER WITH A GROUNDED SECONDARY, CONNECT THE GROUNDED SIDE TO “C ” ON THE CIRCUIT BOARD. 7. IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED, MUST BE REPLACED, USE THE SAME OR EQUIVALENT WIRE. 8. CHECK ALL ELECTRICAL CONNECTIONS INSIDE CONTROL BOX FOR TIGHTNESS. 9. DO NOT ATTEMPT TO OPERATE UNIT UNTIL SERVICE VALVES HAVE BEEN OPENED. 10. USE CONDUCTORS SUITABLE FOR AT LEAST 75ºC (167ºF). DIP SWITCH SETTINGS 30 MINUTES 30 1 2 3 OR (DEFAULT) 60 MINUTES 90 MINUTES 1 2 3 60 1 2 3 OR 120 MINUTES 120 1 2 3 ON 1 2 3 QUIET SHFT OFF (DEFAULT) OR 90 FIELD SELECTABLE OPTIONS FOR TIME PERIOD BETWEEN DEFROST CYCLES (MINUTES) SPEED UP JUMPERED TEST PINS (USE METAL OBJECT), FIELD SPEED-UP CYCLE 1) MOMENTARILY SHORT PINS AND RELEASE TO BYPASS COMPRESSOR OFF DELAY.