HP H2H3, N2H3 SEQUENCE OF OPERATION

INSTALLATION INSTRUCTIONS						3-phase R-22 Split System Heat Pump
Figure 16					R-22 Required Liquid Line
					Temperature (°F) - Cooling Mode
		Rating Plate (required)						Rating Plate (required)
Measured Liquid	Subcooling Temperature (°F)					Measured Liquid	Subcooling Temperature (°F)
	5		10	15	20		5		10	15	20
Pressure (psig)						Pressure (psig)
134	71		66	61	56	233	107		102	97	92
141	74		69	64	59	243	110		105	100	95
148	77		72	67	62	253	113		108	103	98
156	80		75	70	65	264	116		111	106	101
163	83		78	73	68	274	119		114	109	104
171	86		81	76	71	285	122		117	112	107
179	89		84	79	74	297	125		120	115	110
187	92		87	82	77	309	128		123	118	113
196	95		90	85	80	321	131		126	121	116
205	98		93	88	83	331	134		129	124	119
214	101		96	91	86	346	137		132	127	122
223	104		99	94	89	359	140		135	130	125

SEQUENCE OF OPERATION

A. COOLING MODE B. HEATING MODE

On a call for cooling, the thermostat makes circuits R-O, R-Y, and R-G. Circuit R-O energizes reversing valve, switching it to cooling position. Circuit R-Y energizes contactor, starting outdoor fan motor and compressor. Circuit R-G energizes indoor unit blower relay, starting indoor blower motor.

When thermostat is satisfied, its contacts open, de-energizing contactor and blower relay. Compressor and motors stop.

NOTE: If indoor unit is equipped with a time-delay relay circuit, the blower runs an additional length of time to increase system efficiency. (Applies to both cooling and heating modes.)

NOTE: Low ambient cooling feature allows unit to operate safely in cooling mode down to 0° F outdoor ambient.

On a call for heating, the thermostat makes circuits R-Y and R-G (circuit R-O is NOT made, and the reversing valve stays in the de-energized, heating position). Circuit R-Y energizes contactor, starting outdoor fan motor and compressor. Circuit R-G energizes indoor blower relay, starting blower motor. If the room temperature continues to fall, circuit R-W2 is made through the second-stage room thermostat bulb. Circuit R-W2 energizes a sequencer, bringing on the first bank supplemental electric heat and providing electrical potential to the second heater sequencer (if used). If outdoor temperature falls below the setting of the outdoor thermostat (field-installed option), contacts close to complete the circuit and bring on the second bank of supplemental electric heat.

When the thermostat is satisfied, its contacts open, de-energizing contactor, blower relay, and sequencer. Compressor, motors, and heaters stop.

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