Specifications

Table 33 — Alarm and Alert Codes (cont)
ALARM/ALERT
CODE
ALARM OR
ALERT
DESCRIPTION
WHY WAS THIS
ALARM GENERATED?
ACTION TAKEN
BY CONTROL
RESET
METHOD
PROBABLE
CAUSE
68 Alert Circuit B High Dis-
charge Pressure
SCT > MCT_SP + 5 F
(2.8 C)
Circuit shut down Automatic** Faulty transducer/high
pressure switch, low/
restricted condenser
air/water flow.††
70 Alert High Leaving Chilled
Water Temperature
LCW read > LCW Delta
Alarm limit and total ca-
pacity is 100% and cur-
rent LCW > LCW
reading 1 minute ago
Alert only. None Automatic Building load greater
than unit capacity, low
water/brine flow, or
compressor fault. Check
for other alarms or
alerts.
71 Alert Circuit A Low Oil Level Level switch input open
for 4th time in same
day.
Circuit A shut down Manual Low oil level, failed
switch, wiring error,
failed DSIO module
72 Alert Circuit B Low Oil Level Level switch input open
for 4th in same day.
Circuit B shut down Manual Low oil level, failed
switch, wiring error,
failed DSIO module
73 Alert Circuit A Low Discharge
Superheat
Superheat <5 F (2.8 C)
for 10 minutes
Circuit A shut down Manual Faulty thermistor,
transducer or EXV or
Economizer. Motor cool-
ing solenoid stuck open.
74 Alert Circuit B Low Discharge
Superheat
Superheat <5 F (2.8 C)
for 10 minutes
Circuit B shut down Manual Faulty thermistor,
transducer or EXV or
Economizer. Motor cool-
ing solenoid stuck open.
75 Alarm Comp. A1 Max. Oil
Delta P, check oil line
(Discharge press − Oil
press) >100 PSI for
more than 5 seconds
Comp. A1 shut down Manual Plugged oil filter, closed
oil valve, bad oil sole-
noid, compressor oil
check valve stuck, oil
line check valve stuck,
plugged oil strainer
76 Alarm Comp. A2 Max. Oil
Delta P, check oil line
(Discharge press − Oil
press) >100 PSI for
more than 5 seconds
Comp. A2 shut down Manual Plugged oil filter, closed
oil valve, bad oil sole-
noid, compressor oil
check valve stuck, oil
line check valve stuck,
plugged oil strainer
77 Alarm Comp. B1 Max. Oil
Delta P, check oil line
(Discharge press − Oil
press) >100 PSI for
more than 5 seconds
Comp. B1 shut down Manual Plugged oil filter, closed
oil valve, bad oil sole-
noid, compressor oil
check valve stuck, oil
line check valve stuck,
plugged oil strainer
78 Alarm Comp. B2 Max. Oil
Delta P, check oil line
(Discharge press − Oil
press) >100 PSI for
more than 5 seconds
Comp. B2 shut down Manual Plugged oil filter, closed
oil valve, bad oil sole-
noid, compressor oil
check valve stuck, oil
line check valve stuck,
plugged oil strainer
79 Alarm Comp. A1 Failed Oil
Solenoid
Diff. Oil pressure
>2.5 PSI during period
after oil pump starts and
before oil solenoid opens
Comp. A1 not allowed
to start
Manual Faulty oil solenoid valve
80 Alarm Comp. A2 Failed Oil
Solenoid
Diff. Oil pressure
>2.5 PSI during period
after oil pump starts and
before oil solenoid opens
Comp. A2 not allowed
to start
Manual Faulty oil solenoid valve
81 Alarm Comp. B1 Failed Oil
Solenoid
Diff. Oil pressure
>2.5 PSI during period
after oil pump starts and
before oil solenoid opens
Comp. B1 not allowed
to start
Manual Faulty oil solenoid valve
82 Alarm Comp. B2 Failed Oil
Solenoid
Diff. Oil pressure
>2.5 PSI during period
after oil pump starts and
before oil solenoid opens
Comp. B2 not allowed
to start
Manual Faulty oil solenoid valve
LEGEND
CCN — Carrier Comfort Network
CPM — Compressor Protection Module
DGT — Discharge Gas Temperature
EWT — Entering Water Temperature
EXV — Electronic Expansion Valve
FSM — Flotronic™ System Manager
HPS — High-Pressure Switch
LCW — Leaving Chilled Water
LWT — Leaving Water Temperature
MCT
SP — Maximum Condensing Temperature Set Point
MTA — Compressor Must Trip Amps
SCT — Saturated Condensing Temperature
SST — Saturated Suction Temperature
W/C — Water-Cooled
WSM — Water System Manager
*Current and voltage imbalance alarms x.25 and x.55 may be changed to
warnings x.27 and x.57 after successful start-up of the chiller.
†Compressors are equipped with 2 motor winding temperature ther-
mistors. Verify first that the problem is not a wiring error before using backup
thermistor.
**Reset automatic first time, manual if repeated on the same date.
††Note that the high-pressure switch should trip before this alert is generated.
Check HPS operation if this alert is generated.
NOTES:
1. Low Oil Pressure Alert Criteria and Set Points
Where: P
d
= Discharge pressure, P
s
= Suction pressure,
P
o
= Oil pressure and P
e
= Economizer pressure
Two oil pressure set points are used. Oil Set point 1 is always 15 psig.
a. If (P
d
−P
s
) <125, then Oil Set point 2 = 0.235 x (P
d
−P
s
) + 0.588
b. If (P
d
−P
s
) > = 125 and <165, then Oil Set point2=2.0x(P
d
−P
s
)
− 220.0
c. If (P
d
−P
s
) > = 165, then Oil Set point 2 = 0.6364 x (P
d
−P
s
) + 5.0
The 2 set points are used by the control for the Low Oil Pressure alert trip
criteria below:
a. Oil Pressure is ignored during the first 5 seconds after a compressor is
started.
b. In period between 5 and 30 seconds after starting, the alert will be gen-
erated if (P
o
−P
e
) < [(Oil Set point 1)/30] x (Compressor Run time in
seconds) for 3 consecutive readings
c. After 30 seconds run time, the alert will be generated if:
1) (P
o
−P
e
) < Oil Set point 1 for 15 seconds OR
2) (P
o
−P
s
) < Oil Set point 2 for 25 seconds
2. (P
o
−P
e
) is the Oil pressure differential displayed in for Circuit A
and for Circuit B.
48