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Pressure relief valves located on cooler and condenser shells
and 30HXA oil separator shells have
tions for relief. The 30GX oil separators have
flare connections. Some local building codes require that re-
lieved gases be removed. This connection allows conform-
ance to this requirement.
Control Modules
Turn controller power off before servicing controls. This
ensures safety and prevents damage to controller.
PROCESSOR MODULE (PSIO-1), HIGH-VOLTAGE
RELAY MODULE (DSIO-HV), AND EXV DRIVER
MODULE (DSIO-EXV), 12/6 MODULE (PSIO-2) — The
PSIO and DSIO modules all perform continuous diagnostic
evaluations of the condition of the hardware. Proper opera-
tion of these modules is indicated by LEDs on the front sur-
face of the DSIOs, and on the top horizontal surface of the
PSIOs.
RED LED — Blinking continuously at a 1 to 2 second rate
indicates proper operation. Lighted continuously indicates a
problem requiring replacement of module. Off continuously
indicates power should be checked. If there is no input power,
check fuses. If fuse is bad, check for shorted secondary of
transformer, tripped circuit breaker or bad module. On the
PSIO module, if the light is blinking at a rate of twice per
second, the module should be replaced.
GREEN LED — On a PSIO module, this is the green LED
closest to COMM connectors. The other green LED on mod-
ule indicates external communications, when used. Green LED
should always be blinking when power is on. It indicates
modules are communicating properly. If green LED is not
blinking, check red LED. If red LED is normal, check mod-
ule address switches. Correct addresses are as follows:
PSIO-1 (Processor Module)
CPM-A1 (Protection Module) — 21
CPM-A2 (Protection Module) — 29
CPM-B1 (Protection Module) — 37
DSIO (EXV Driver Module) — 50
DSIO-HV (Relay Module)
PSIO-2 (12/6 I/O Module)
The first number of the address for a DSIO module should
be set on the switch closest to the silver mounting plate.
If all modules indicate communication failure, check
COMM plug on PSIO-1 module for proper seating. If a good
connection is assured and condition persists, replace PSIO-1
module.
If only a DSIO module indicates communication failure,
check COMM plug on that module for proper seating. If a
good connection is assured and the condition persists, re-
place the DSIO module.
All system operating intelligence rests in the PSIO-1 mod-
ule, the module that controls unit. This module monitors
conditions through input and output ports and through
DSIO modules (high-voltage relay module and EXV driver
module).
The machine operator communicates with microproces-
sor through keypad and display module. Communication be-
tween PSIO and other modules is accomplished by a 3-wire
sensor bus. These 3 wires run in parallel from module to
module.
⁄
-in. NPT connec-
3
4
1
⁄
-in. male
2
— 01
— 62
— 74
On sensor bus terminal strips, terminal 1 of PSIO module
is connected to terminal 1 of each of the other modules.
Terminals 2 and 3 are connected in the same manner. See
Fig. 24. If a terminal 2 wire is connected to terminal 1, sys-
tem does not work.
In the 30GX,HX control box, the processor module
(PSIO-1), DSIO-HV, keypad and display module and 5 vdc
power supply are all powered from a common 21 vac power
source (PSIO-1 and HSIO powered from 24 vac source on
30HX units) which connects to terminals 1 and 2 of the power
connector on each module. A separate source of 21 vac power
is used to power the PSIO-2 module and liquid level sensor
heaters. A separate 12.5 vdc power source is used for
the DSIO-EXV module through terminals 1 and 2 on the
power connector. The CPM modules are connected to 24 vac
power sources. Refer to Table 43 for control troubleshooting
information.
Carrier Comfort Network (CCN) Interface —
30GX,HX chiller units can be connected to the CCN if de-
sired. The communication bus wiring is a shielded, 3-conductor
cable with drain wire and is supplied and installed in the
field. The system elements are connected to the communi-
cation bus in a daisy chain arrangement as shown in Fig. 24.
The positive pin of each system element communication con-
nector must be wired to the positive pins of the system el-
ements on either side of it. This is also required for the nega-
tive and signal ground pins of each system element. Wiring
connections for CCN should be made at the COMM1 plug
on the PSIO-1 module. Consult the CCN Contractor's Manual
for further information.
NOTE: Conductors and drain wire must be 20 AWG (Amer-
ican Wire Gage) minimum stranded, tinned copper. In-
dividual conductors must be insulated with PVC, PVC/
nylon, vinyl, Teflon, or polyethylene. An aluminum/polyester
100% foil shield and an outer jacket of PVC, PVC/nylon,
chrome vinyl, or Teflon with a minimum operating tem-
perature range of −20 C to 60 C is required. Wire manu-
factured by Alpha (2413 or 5463), American (A22503), Belden
(8772), or Columbia (02525) meets the above mentioned
requirements.
It is important when connecting to a CCN communication
bus that a color coding scheme be used for the entire net-
work to simplify the installation. It is recommended that red
be used for the signal positive, black for the signal negative,
and white for the signal ground. Use a similar scheme for
cables containing different colored wires.
At each system element, the shields of its communication
bus cables must be tied together. If the communication bus
is entirely within one building, the resulting continuous shield
must be connected to a ground at one point only. If the com-
munication bus cable exits from one building and enters an-
other, the shields must be connected to grounds at the light-
ning suppressor in each building where the cable enters or
exits the building (one point per building only). To connect
the unit to the network:
1. Turn off power to the control box.
2. Cut the CCN wire and strip the ends of the red (+), white
(ground), and black (−) conductors. (Substitute appropri-
ate colors for different colored cables.)
64
The
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Table of Contents
Troubleshooting
