Raypak XTherm Series Installation & Operating Instructions Manual page 27

run communication cables parallel with, or close to
or against, high voltage (120 volt or greater) wir-
ing. Raypak recommends that the total maximum
length of each set of communication bus cables
not exceed 200 feet.
3. Connect the FT_BUS wires to the PIM by press-
ing down on the slots with a small screwdriver
and then inserting the wires into the holes. See
Fig. 31.
Fig. 31: FT_BUS Wire Connection
Cascade System Pump and
Sensor Wiring
1. On the boiler designated as the Master, connect
the system pump enable wiring to the terminal
block at the rear of the unit. The connections are
dry contacts rated for pilot duty only (5A maxi-
mum).
2. Connect the injection pump contactor (field-sup-
plied) coil wires in parallel with the mounted boiler
primary pump contactor coil located at the rear of
the unit. Refer to wiring diagram provided with unit.
3. Connect the system supply sensor to terminals 6
and 7 on the field wiring strip located on the Master
boiler (See Fig. 29).
4. Connect the Outdoor sensor (if used) to terminals
8 and 9 on the field wiring strip located on the
Master boiler (See Fig. 29).
Fig. 32: XTherm Cascade Master Pumps
5. Connect the Enable/Disable wiring to terminals
11 and 12 on the field wiring strip located on the
Master boiler (See Fig. 29). This connection must
be provided through dry contacts closure.
NOTE: The dry contacts closure can come from a
room thermostat or a remote relay. No power of any
kind should be applied to either of these terminals.
Cascade Follower Pump
and Sensor Wiring
1. Once the primary boiler has been identified, addi-
tional boilers will be designated as follower boilers.
Ensure DIP switch 2 on each follower VERSA is
set to the OFF/Down position.
2. For each follower boiler, connect injection pump
contactor (field-supplied) coil wires in parallel with
the mounted boiler primary pump contactor coil
located at the rear of the unit. Refer to wiring dia-
gram provided with unit.
3. For Cascade configurations System pump (all
models) and DHW pump (H models only), Follower
outputs must be connected in parallel respectively
in order to support operation during "Limp Along"
mode. For detailed wiring instructions see VERSA
IC manual, catalog 5000.72.
Fig. 33: VERSA Follower
Modbus BMS Communication
The VERSA IC control is equipped as standard with a
communications port for connectivity to building auto-
mation via Modbus protocol. Refer to the VERSA IC
manual (5000.72) for further information.
27