Carrier 48/50AJ specifications Time Guard Display Table, Software Version Numbers Display Table

Table 112 — Time Guard Display Table

ITEM	EXPANSION	RANGE	UNITS	POINT	WRITE STATUS
TMGD	TIMEGUARDS
TG.A1	Compressor A1 Timeguard			CMPA1_TG
TG.A2	Compressor A2 Timeguard			CMPA2_TG
TG.B1	Compressor B1 Timeguard			CMPB1_TG
TG.B2	Compressor B2 Timeguard			CMPB2_TG
TG.H1	Heat Relay 1 Timeguard			HS1_TG
TG.H2	Heat Relay 2 Timeguard			HS2_TG
TG.H3	Heat Relay 3 Timeguard			HS3_TG
TG.H4	Heat Relay 4 Timeguard			HS4_TG
TG.H5	Heat Relay 5 Timeguard			HS5_TG
TG.H6	Heat Relay 6 Timeguard			HS6_TG

Table 113 — Software Version Numbers Display Table

ITEM	EXPANSION	RANGE	UNITS	POINT	WRITE STATUS
VERS	SOFTWARE VERSION NUMBERS
MBB	CESR131343-xx-xx			string
ECB1	CESR131249-xx-xx			string
ECB2	CESR131249-xx-xx			string
SCB	CESR131226-xx-xx			string
CEM	CESR131174-xx-xx			string
MARQ	CESR131171-xx-xx			string
NAVI	CESR130227-xx-xx			string

Alarms and Alerts — There are a variety of different alerts and alarms in the system.

•P — Pre-Alert: Part of the unit is temporarily down. The alarm is not broadcast on the CCN network. The alarm relay is not energized. After an allowable number of retries, if the function does not recover, the pre-alert will be upgraded to an alert or an alarm.

•T — Alert: Part of the unit is down, but the unit is still partially able to provide cooling or heating.

•A — Alarm: The unit is down and is unable to provide cooling or heating.

All alarms are displayed with a code of AXXX where the A is the category of alarm (Pre-Alert, Alert, or Alarm) and XXX is the number.

The response of the control system to various alerts and alarms depends on the seriousness of the particular alert or alarm. In the mildest case, an alert does not affect the operation of the unit in any manner. An alert can also cause a “strike.” A “striking” alert will cause the circuit to shut down for 15 min- utes. This feature reduces the likelihood of false alarms causing a properly working system to be shut down incorrectly. If three strikes occur before the circuit has an opportunity to show that it can function properly, the circuit will strike out, causing the shutdown alarm for that particular circuit. Once activated, the shutdown alarm can only be cleared via an alarm reset.

Circuits with strikes are given an opportunity to reset their strike counter to zero. As discussed above, a strike typically causes the circuit to shut down. Fifteen minutes later, that circuit will once again be allowed to run. If the circuit is able to run for 1 minute, its replacement circuit will be allowed to shut down (if not required to run to satisfy requested stages). How- ever, the “troubled” circuit must run continuously for 5 minutes with no detectable problems before the strike counter is reset to zero.

All the alarms and alerts are summarized in Table 114.

DIAGNOSTIC ALARM CODES AND POSSIBLE CAUSES

T051, P051 (Circuit A, Compressor 1 Failure)

T052, P052 (Circuit A, Compressor 2 Failure)

T055, P055 (Circuit B, Compressor 1 Failure)

T056, P056 (Circuit B, Compressor 2 Failure) — 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

operation. When this occurs, the control turns off the compres- sor and logs a strike for the respective circuit. These alerts reset automatically.

If the current sensor board reads OFF while the compressor relay has been commanded ON for a period of 4 continuous seconds, an alert is generated.

Any time this alert occurs, a strike will be called out on the affected compressor. If three successive strikes occur the compressor will be locked out requiring a manual reset or power reset of the circuit board. The clearing of strikes during compressor operation is a combination of 3 complete cycles or 15 continuous minutes of run time operation. So, if there are one or two strikes on the compressor and three short cycles (ON-OFF, ON-OFF, ON-OFF) less than 15 minutes each occur, the strikes will be reset to zero for the affected compres- sor. Also, if the compressor turns on and runs for 15 minutes straight with no compressor failure, the compressor’s strikes are cleared as well.

NOTE: Until the compressor is locked out, for the first two strikes, the alert will not be broadcast to the network, nor will the alarm relay be closed.

The possible causes are:

•High-pressure switch (HPS) open. The HPS is wired in series with compressor relays on the MBB. If the high-pres- sure switch opens during compressor operation, the com- pressor stops, and the CS no longer detects current, causing the control to activate this alert.

For 48/50AJ,AK,AW,AY units:

•Compressor internal overload protection is open. The inter- nal overloads are used on the Scroll Tech compressors (black) and smaller Maneurop compressors used on the size 020, 025, 027, 030, 035 units and 040 A1, A2 compressors.

•Internal compressor temperature sensor trip. The large Maneurop compressors (blue) used on the size 040 (B1, B2), 050, and 060 units have an internal temperature sensor.

•Circuit breaker trip. The compressors are protected from short circuit by a breaker in the control box. On the size 020-035 and 040 A1, A2 units there is one breaker per two compressors and on the size 040 (B1, B2), 050, and 060 compressors there is one breaker per compressor because there are not internal overloads.

•Wiring error. A wiring error might not allow the compressor to start.

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