Carrier 48/50AJ specifications Fans in Service Test Mode — Upon entering the

However, it is important to note that the user can leave a Service Test mode to view any of the local display modes and the control will remain in the Service Test mode.

Independent Outputs — The INDP sub-mode items can be turned on and off regardless of the other category states. For example, the alarm relay can be forced on in the INDP sub-mode and will remain on if compressor relays are request- ed in the COOL sub-mode.

Fans in Service Test Mode — Upon entering the

FANS sub-mode, the user will be able to turn the supply fan on and off, set the supply fan VFD speed, and turn the condenser fans on and off.

Cooling in Service Test Mode — The COOL sub- mode offers different cooling service tests.

The user has manual relay control of individual compres- sors. If the user energizes mechanical cooling, the supply fan and the outdoor fans will be started automatically. During mechanical cooling, the unit will protect itself. Compressor diagnostics are active, monitoring for high discharge pressure, low suction pressure, etc. The user can also turn the hot gas bypass valve on and off.

NOTE: It is crucial that proper compressor rotation be verified during the service test. Each compressor must be tested

individually. After starting each compressor, the control will check the suction pressure after 5 seconds of run time. If the control does not see a sufficient decrease in suction pressure after 5 seconds, mechanical cooling will be shut down, and an alarm will be generated (A140). This alarm requires a manual reset. If this alarm occurs, do not attempt a restart of the compressor and do not attempt to start any other compressors until the wiring to the unit has been corrected.

Heating in Service Test Mode — If unit has a ther- mostat connected (C.TYP = 3 or 4), install the RED jumper wires between TB4, terminals R (1), W2 (3) and W1 (4). Ter- minal block TB4 is located in the unit control box. Remember to disconnect these jumpers when Test Mode is completed. The Heat Test Mode sub-mode will offer automatic fan start-up if the unit is not a gas heat unit. On gas heat units, the IGC feed- back from the gas control units will bring the fan on as required.

Within this sub-mode, the user has control of heat relays 1 to 6. The user can also turn on the requested heat stage.

NOTE: When service test has been completed, if unit has a thermostat connected (C.TYP = 3 or 4), remove the RED jumper wires at TB4, terminals R (1), W2 (3) and W1 (4). Terminal block TB4 is located in the unit control box. Store these jumpers in the unit control box for future use.

Table 41 — Service Test

ITEM	EXPANSION	RANGE	UNITS	POINT	WRITE STATUS
TEST	Service Test Mode	ON/OFF		MAN_CTRL
STOP	Local Machine Disable	YES/NO		UNITSTOP	config
S.STP	Soft Stop Request	YES/NO		SOFTSTOP	forcible
FAN.F	Supply Fan Request	YES/NO		SFANFORC	forcible
F.4.CH	4 in. Filter Change Mode	YES/NO		FILT4CHG
INDP	TEST INDEPENDENT OUTPUTS
ECON	Economizer Act.Cmd.Pos.			ECONCTST
E.PWR	Economizer Power Test			ECONPTST
E.CAL	Calibrate the Economizer?			ECON_CAL
E.VFD	Exhaust Fan VFD Speed	0-100	%	EFAN_VFD
PE.A	Power Exhaust Relay A			PE_A_TST
PE.B	Power Exhaust Relay B			PE_B_TST
PE.C	Power Exhaust Relay C			PE_C_TST
H.I.R	Heat Interlock Relay	ON/OFF		HIR_TST
ALRM	Remote Alarm/Aux Relay	ON/OFF		ALRM_TST
FANS	TEST FANS
S.FAN	Supply Fan Relay	ON/OFF		SFAN_TST
S.VFD	Supply Fan VFD Speed	0-100	%	SGVFDTST
CD.F.A	Condenser Fan Circuit A	ON/OFF		CNDA_TST
CD.F.B	Condenser Fan Circuit B	ON/OFF		CNDB_TST
COOL	TEST COOLING
A1	Compressor A1 Relay	ON/OFF		CMPA1TST
A2	Compressor A2 Relay	ON/OFF		CMPA2TST
MLV	Min. Load Valve (HGBP)	ON/OFF		MLV_TST
B1	Compressor B1 Relay	ON/OFF		CMPB1TST
B2	Compressor B2 Relay	ON/OFF		CMPB2TST
HEAT	TEST HEATING
HT.ST	Requested Heat Stage	0-MAX		HTST_TST
HT.1	Heat Relay 1	ON/OFF		HS1_TST
HT.2	Heat Relay 2	ON/OFF		HS2_TST
HT.3	Relay 3 W1 Gas Valve 2	ON/OFF		HS3_TST
HT.4	Relay 4 W2 Gas Valve 2	ON/OFF		HS4_TST
HT.5	Relay 5 W1 Gas Valve 3	ON/OFF		HS5_TST
HT.6	Relay 6 W2 Gas Valve 3	ON/OFF		HS6_TST

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