Carrier 50PSH, PSD006-070, PSV instruction manual Operating Limits, Unit Start-Up Cooling Mode

Deluxe D Control Accessory Relay Configura- tions — The following accessory relay settings are applica- ble for Deluxe D control:

CYCLE WITH FAN — In this configuration, the accessory relay 1 will be ON any time the Fan Enable relay is on.

CYCLE WITH COMPRESSOR — In this configuration, the accessory relay 2 will be ON any time the Compressor relay is on.

DIGITAL NIGHT SET BACK (NSB) — In this configura- tion, the relay will be ON if the NSB input is connected to ground C.

NOTE: If there are no relays configured for digital NSB, then the NSB and override (OVR) inputs are automatically config- ured for mechanical operation.

MECHANICAL NIGHT SET BACK — When NSB input is connected to ground C, all thermostat inputs are ignored. A thermostat set back heating call will then be connected to the OVR input. If OVR input becomes active, then the Deluxe D control will enter night low limit (NLL) staged heating mode. The NLL staged heating mode will then provide heating dur- ing the NSB period.

WATER VALVE (SLOW OPENING) — If relay is configured for Water Valve (slow opening), the relay will start 60 seconds prior to starting compressor relay.

OUTSIDE AIR DAMPER (OAD) — If relay is configured for OAD, the relay will normally be ON any time the Fan Enable relay is energized. The relay will not start for 30 minutes fol- lowing a return to normal mode from NSB, when NSB is no longer connected to ground C. After 30 minutes, the relay will start if the Fan Enable is set to ON.

CAUTION

To avoid equipment damage, DO NOT leave system filled in a building without heat during the winter unless anti- freeze is added to system water. Condenser coils never fully drain by themselves and will freeze unless winterized with antifreeze.

START-UP

Use the procedure outlined below to initiate proper unit start-up.

NOTE: This equipment is designed for indoor installation only.

Operating Limits

ENVIRONMENT — This equipment is designed for indoor installation ONLY. Extreme variations in temperature, humidi- ty and corrosive water or air will adversely affect the unit per- formance, reliability and service life.

POWER SUPPLY — A voltage variation of ± 10% of name- plate utilization voltage is acceptable.

UNIT STARTING CONDITIONS — Units start and operate in an ambient temperature of 45 F with entering-air tempera- ture at 50 F, entering-water temperature at 60 F and with both air and water at the flow rates used.

NOTE: These operating limits are not normal or continuous operating conditions. Assume that such a start-up is for the purpose of bringing the building space up to occupancy tem- perature. See Table 18 for operating limits.

WARNING

When the disconnect switch is closed, high voltage is present in some areas of the electrical panel. Exercise cau- tion when working with the energized equipment. Failure to heed this warning may result in personal injury.

1.Restore power to system.

2.Turn thermostat fan position to ON. Blower should start.

3.Balance airflow at registers.

4.Adjust all valves to the full open position and turn on the line power to all heat pump units.

5.Operate unit in the cooling cycle. Refer to Table 14 for unit operating limits.

NOTE: Three factors determine the operating limits of a unit:

(1)entering air temperature, (2) water temperature and (3) ambient temperature. Whenever any of these factors are at a minimum or maximum level, the other two factors must be at a normal level to ensure proper unit operation. See Table 18.

Table 18 — Operating Limits —

50PSH, PSV, PSD Units

AIR LIMITS	COOLING (F)	HEATING (F)
Min. Ambient Air	45	39
Rated Ambient Air	80.6	68
Max. Ambient Air	110	85
Min. Entering Air	50	40
Rated Entering Air db/wb	80/67	68
Max. Entering Air db/wb	110/83	80
WATER LIMITS
Min. Entering Water	30	20
Normal Entering Water	50-110	30-70
Max. Entering Water	120	90
LEGEND

db — Dry Bulb wb — Wet Bulb

NOTE: Value in heating column is dry bulb only. Any wet bulb reading is acceptable.

Scroll Compressor Rotation — It is important to be certain compressor is rotating in the proper direction. To determine whether or not compressor is rotating in the proper direction:

1.Connect service gages to suction and discharge pressure fittings.

2.Energize the compressor.

3.The suction pressure should drop and the discharge pressure should rise, as is normal on any start-up.

If the suction pressure does not drop and the discharge pressure does not rise to normal levels:

1.Turn off power to the unit. Install disconnect tag.

2.Reverse any two of the unit power leads.

3.Reapply power to the unit and verify pressures are correct.

The suction and discharge pressure levels should now move to their normal start-up levels.

When the compressor is rotating in the wrong direction, the unit makes more noise and does not provide cooling.

After a few minutes of reverse operation, the scroll com- pressor internal overload protection will open, thus activating the unit lockout. This requires a manual reset. To reset, turn the thermostat on and then off.

NOTE: There is a 5-minute time delay before the compressor will start.

Unit Start-Up Cooling Mode

1.Adjust the unit thermostat to the warmest position. Slowly reduce the thermostat position until the compres- sor activates.

2.Check for cool air delivery at unit grille a few minutes after the unit has begun to operate.

3.Verify that the compressor is on and that the water flow rate is correct by measuring pressure drop through the heat exchanger using P/T plugs. See Table 19. Check the elevation and cleanliness of the condensate lines; any dripping could be a sign of a blocked line. Be sure the condensate trap includes a water seal.

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