26
VERSA
MASTER
MASTER
FOLLOWERS
Fig. 27: XTherm Cascade System Wiring
Fig. 28: XTherm Cascade Master-Pumps
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 system supply sensor to terminals 6
and 7 on the field wiring strip located on the Master
PIM™ (See Fig. 25).
3. Connect the Outdoor sensor (if used) to terminals
8 and 9 on the field wiring strip located on the
Master boiler (See Fig. 25).
4. Connect the Enable/Disable wiring to terminals 11
and 12 on the field wiring strip located on the
Master boiler (See Fig. 25). This connection must
be provided through dry contacts closure.
