CPC MultiFlex PAK, Руководство пользователя

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12 • MultiFlex I/O Board Operator’s Guide 026-1712 Rev 3 03-JAN-2008
4.2. The Relay Outputs
4.2.1. Output Types Supported by
the MultiFlex PAK
4.2.2. The PAK Default
Output Assignments
4.2.3. Wiring
The MultiFlex PAK boards have Form C
relay contacts. Figure 4-3 shows how to wire the
three-terminal Form C contact.
One wire of the two-wire connection should
always be connected to the middle terminal. The
second wire must either be connected to the N.C.
terminal (if you want the path to be closed when
the relay is de-energized) or the N.O. terminal (if
you want the path to be open during power fail-
ure).
The contacts you choose also affect what the
board’s fail-safe dip switch will need to be set to
for proper operation. Refer to
Table 4-5 and
Table 4-6 on page 13.
4.2.4. Output Fail-Safe Dip Switch-
es
When a controller calls for a MultiFlex relay
output to be ON, it sends a command to the Mul-
tiFlex to turn the output to the ON state (signi-
fied by the output LED being ON). The behavior
of the relay when it is ON is determined by the
position of the
fail-safe switch . The fail-safe
switches for the outputs are on a switch bank at
the bottom right corner the plug-in output mod-
ule. Each switch corresponds to an output on the
board (switch #1 = output #1, etc.).
Table 4-5 and Table 4-6 show how the fail-
safe switch and Form C contacts should be con-
figured based on how you want the output to
perform during both normal operation and dur-
ing network/power loss.
Note: There are not many cases where you
would want a relay to be OPEN when called to
be ON. For most applications, you will want to
set the fail-safe switch to UP so that an ON com-
mand from the controller will close the relay.
Output Type Description
Comp Grp1-8 Compressor Group output 1-8
Fan Stage 1-4 Fan Stage output 1-4
Liq Inject Condenser Liquid Injection
valve
Cond Spray Condenser Spray valve
Alarm Compressor discharge temper-
ature sensors for compressors
#1 through #8
VSD Fan En-
able
"Run" input for an inverter oper-
ating the variable-speed fan(s)
VSD Bypass Bypass input for an inverter op-
erating the variable-speed
fan(s)
VSD Reset Reset input for an inverter oper-
ating the variable-speed fan(s)
Table 4-3 - MultiFlex PAK Output Types
Relay Output # Definition
1 Comp Grp 1
2 Comp Grp 2
3 Comp Grp 3
4 Comp Grp 4
5 Comp Grp 5
6 Comp Grp 6
7 Comp Grp 7
8 Comp Grp 8
Table 4-4 - MultiFlex PAK Default Outputs
Figure 4-3 - Form C Contact Wiring
N.C. N.O. N.C. N.O.
RELAY IS
CLOSED
ON POWER
FAILURE
RELAY IS
OPEN ON
POWER
FAILURE