Carrier 30RAP010-060 Alert GENERATED?, Ccn, Csb, Emm, Ewt, Exv, Hsm, Lcw, Lwt, Mbb, Oat

Table 42 — Alarm and Alert Codes (cont)

ALARM/	ALARM		WHY WAS THIS	ACTION TAKEN	RESET	PROBABLE
ALERT	OR	DESCRIPTION	ALARM
				BY CONTROL	METHOD	CAUSE
CODE	ALERT		GENERATED?
			Strainer Service
		Strainer Blowdown	Countdown (S.T.DN)			Routine strainer
T302			expired. Complete strainer
	Alert	Scheduled		None	Automatic	maintenance
			blowdown and enter 'YES'
		Maintenance Due				required
			for Strainer Maintenance
			Done (S.T.MN) item.
			Coil Service Countdown
			(C.L.DN) expired.			Routine condenser
T303		Condenser Coil	Complete condenser coil
	Alert			None	Automatic	coil maintenance
		Maintenance Due	cleaning and enter 'YES'
						required
			for Coil Maintenance Done
			(C.L.MN) item.
T500	Alert	Current Sensor Board	Alert occurs when CSB out-	Compressor A1 shut	Automatic	CSB failure.
		A1 Failure	put is a constant high value	down		Wiring error.
T501	Alert	Current Sensor Board	Alert occurs when CSB out-	Compressor A2 shut	Automatic	CSB failure.
		A2 Failure	put is a constant high value	down		Wiring error.
T502	Alert	Current Sensor Board	Alert occurs when CSB out-	Compressor A3 shut	Automatic	CSB failure.
		A3 Failure	put is a constant high value	down		Wiring error.
T503	Alert	Current Sensor Board	Alert occurs when CSB out-	Compressor B1 shut	Automatic	CSB failure.
		B1 Failure	put is a constant high value	down		Wiring error.
T504	Alert	Current Sensor Board	Alert occurs when CSB out-	Compressor B2 shut	Automatic	CSB failure.
		B2 Failure	put is a constant high value	down		Wiring error.
T505	Alert	Current Sensor Board	Alert occurs when CSB out-	Compressor B3 shut	Automatic	CSB failure.
		B3 Failure	put is a constant high value	down		Wiring error.
T950	Alert	Loss of Communication	No communications have	WSM forces removed.	Automatic	Failed module, wiring
		with Water System	been received by the MBB	Chiller runs under own		error, failed
		Manager	within 5 minutes of last	control		transformer, loose
			transmission			connection plug,
						wrong address
T951	Alert	Loss of Communication	No communications have	CSM forces removed.	Automatic	Failed module, wiring
		with Chillervisor System	been received by the MBB	Chiller runs under own		error, failed
		Manager	within 5 minutes of last	control		transformer, loose
			transmission			connection plug,
						wrong address
T952	Alert	Loss of Communication	No communications have	HSM forces removed.	Automatic	Failed module, wiring
		with Hydronic System	been received by the MBB	Chiller runs under own		error, failed
		Manager	within 5 minutes of last	control		transformer, loose
			transmission			connection plug,
						wrong address
	LEGEND FOR TABLE 42
CCN	— Carrier Comfort Network
CSB	— Current Sensor Board
EEPROM — Electronic Eraseable Programmable Read Only Memory
EMM	— Energy Management Module
EWT	— Entering Fluid Temperature
EXV	— Electronic Expansion Valve
HSM	— Hydronic System Manager
LCW	— Leaving Chilled Water
LWT	— Leaving Fluid Temperature
MBB	— Main Base Board
OAT	— Outdoor-Air Temperature
SCT	— Saturated Condensing Temperature
WSM	— Water System Manager

COMPRESSOR FAILURE ALERTS

T051, T052 (Circuit A Compresser Failures)

T055, T056 (Circuit B Compressor Failures) — Alert codes 051, 052, 055, and 056 are for compressors A1, A2, B1, and B2 respectively. These alerts occur when the current sensor (CS) does not detect compressor current during compressor op- eration. When this occurs, the control turns off the compressor.

If the current sensor board reads OFF while the compressor relay has been commanded ON, an alert is generated.

POSSIBLE CAUSES

Compressor Overload — Either the compressor internal over- load protector is open or the external overload protector (Kri- wan module) has activated. The external overload protector modules are mounted in the compressor wiring junction box. Temperature sensors embedded in the compressor motor wind- ings are the inputs to the module. The module is powered with 24 vac from the units main control box. The module output is a normally closed contact that is wired in series with the com- pressor contactor coil. In a compressor motor overload condi- tion, contact opens, deenergizing the compressor contactor.

Low Refrigerant Charge — If the compressor operates for an extended period of time with low refrigerant charge, the com- pressor ASTP device will open, which will cause the compres- sor to trip on its overload protection device.

Circuit Breaker Trip — The compressors are protected from short circuit by a breaker in the control box.

Wiring Error — A wiring error might not allow the compres- sor to start.

To check out alerts T051-T056:

1.Turn on the compressor in question using Service Test mode. If the compressor does not start, then most likely the problem is one of the following: HPS open, open in- ternal protection, circuit breaker trip, incorrect safety wir- ing, or incorrect compressor wiring.

2.If the compressor does start, verify it is rotating in the cor- rect direction.

IMPORTANT: Prolonged operation in the wrong direction can damage the compressor. Correct rotation can be veri- fied by a gage set and looking for a differential pressure rise on start-up.

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