Carrier 040-420 User Manual

Page 51

Code 30

Reset input failure (4 to 20

Code 31

Demand limit input failure (4 to 20

These codes apply only if unit is configured for these

functions. If

signal is less than 4 or more than

reset or demand limit function is disabled and unit

functions normally. If

signal returns to the acceptable

range, function is automatically enabled.

Code 32

Loss of communication with compressor
relay module (DISO-LV)

Code 33

Loss of communication with EXV relay
module (DSIO-EXV)

If communication is lost with either of these modules,

unit shuts down without

This alarm resets

auto-

matically when communication is restored. The unit starts
up normally after alarm condition is reset. Probable cause
of condition is a faulty or improperly connected plug, wir-
ing error, or faulty module.

Loss of communication can be attributed to a grounded

transformer with a secondary voltage of 21

supplying

the PSIO, DSIO-LV, or 4 IN/4 OUT modules; the
transformer supplying the DSIO-EXV module; or the

transformer supplying PS 1 for the transformers. These

transformers should not be grounded, or serious damage to
controls can result. Check to be sure the

are

not grounded.
NOTE: If a blank

module is downloaded without be-

ing connected to the modules DSIO, this alarm is
energized.
Code 34

Loss of communication with 4 In/4 Out module

This applies only if one or more of the following options

are used:

external temperature reset

4-20

temperature reset

external switch controlled dual set point

switch controlled demand limit

4-20

demand limit

hot gas bypass

If communication is lost with 4 IN/4 OUT module, the

unit shuts off automatically, after finishing

Reset

of alarm is automatic when communication is restored. Start-up
after alarm is remedied follows a normal sequence. Proba-
ble cause of condition is a faulty or improperly connected

plug, wiring error, or faulty module.

Loss of communication can be attributed to a grounded

transformer with a secondary voltage of 21

supplying

the PSIO, DSIO-LV, or 4 IN/4 OUT; the

trans-

former supplying the DSIO-EXV module, or the

trans-

former supplying PS 1 for the transformers. These transformers
should

be grounded, or serious damage to controls can

result. Check to be sure the transformers are not grounded.

Code 36

Low refrigerant pressure, Circuit A

Code 37

Low refrigerant pressure, Circuit B

If suction pressure transducer senses a pressure below set

point for more than 5 minutes at start-up or more than

2 minutes during normal operation, affected circuit shuts
down without going through the

process. Reset is

automatic when pressure reaches 10 psig above set point if
there have been no previous occurrences of this fault on the

same day. If this is a repeat occurrence on same day, then

reset is manual, with LOCAL/ENABLE-STOP-CCN switch,

Factory configured set point is 27 psig for standard chillers
and 12 psig for brine chillers.

Possible causes of fault are low refrigerant charge, faulty

EXV, plugged filter drier, or faulty transducer.
Code 38

Failure to pump out, Circuit A

Code 39

Failure to pump out, Circuit B

The

process is terminated when saturated suc-

tion temperature is 10” F (5.5” C) below temperature at

ginning of

F (5.5” C) below leaving water

temperature or reaches a saturated suction temperature of

-15 F (-26 C). If appropriate saturated suction temperature
is not met within 3 minutes (on 2 consecutive tries}, circuit
shuts down without

Reset is manual with LOCAL/

ENABLE-STOP-CCN Switch, and start-up follows normal

sequence.

Possible causes for this alarm are a bad thermistor or trans-

ducer or a faulty EXV.
Code 40

Low oil pressure, Circuit A

Code 41

Low oil pressure, Circuit

If oil pressure differential is less than set point for more

than 2 minutes at start-up, or more than one minute during
normal operation, affected circuit shuts down without go-
ing through

process, Reset is manual with LOCAL/

ENABLE-STOP-CCN switch, and start-up follows normal
sequence.

Factory configured differential oil pressure is

6 psig.

Possible causes of fault are faulty compressor, EXV, crank-

case heater or transducer, refrigerant overcharge, insuffi-
cient oil charge, or tripped circuit breaker.

Code 42 Cooler freeze protection

If cooler entering or leaving water temperature is below

34 F (1.1 C) for water or more than 8” F (4.4” C) below set
point for brine, unit shuts down without

Chilled

water pump continues to run if controlled by chiller con-
trols. Reset is automatic when leaving water temperature
reaches

F (3” C) above set point, providing there has

been no prior occurrence of this fault the same day. If fault
has occurred previously the same day, reset is manual with
LOCAL/ENABLE-STOP-CCN switch.

Possible causes of fault are low water flow or faulty

thermistor.
Code 43 Low water flow

If any compressors are operating and entering water tem-

perature is 3” F (1.7” C) or more below leaving water tem-

perature for more than one minute, unit shuts down without

Chilled water pump also shuts down. Reset is

manual with LOCAL/ENABLE-STOP-CCN switch, and
start-up follows normal sequence.

This is a suitable method for sensing low water flow be-

cause entering water thermistor is in the cooler shell and
responds more quickly to compressor operation than the leav-
ing water thermistor in the leaving water nozzle, Possible
causes of fault are faulty chilled water pump, control or
thermistor.

Code 44

Low cooler suction temperature, Circuit A

Code 45

Low cooler suction temperature, Circuit B

If saturated suction temperature is less than 32 F (0°C)

and is 20” F (11” C) for water or 30” F

C) for brine or

more below leaving fluid temperature, mode 14 is dis-

played. Unit continues to run, but additional compressors

are not allowed to start, If condition persists for more than

10 minutes, fault code is displayed, and unit shuts down

without

Reset is manual with

STOP-CCN switch, and start-up follows normal sequence.

Possible causes of fault are low refrigerant charge, plugged

filter drier, or a faulty EXV or thermistor.
Code 46

High suction superheat, Circuit A

Code 47

High suction superheat, Circuit B

If EXV is fully open, suction superheat is greater than

75 F (42 C) and saturated evaporator temperature is less
than MOP (maximum operating pressure) for more than 5
minutes, unit shuts down after normal

process.

Reset is manual with LOCAL/ENABLE-STOP-CCN switch,

and start-up follows normal sequence.