For connection
of additional
controllers
Used only with optional reset
control - refer to
instruction
manual 210668
for details
To
thermostats
}
Input Power
120/1/60
To zone
circulators
Refer to Fig 1A for cold start or
Fig. 1B for tankless coil application
EXPANSION
BOIL OUT SUP COM
H
N
24 VAC
R W
ZONE 1
ZONE 1
L N
ZONE 2
L N
ZONE 3
L N
ZONE 4
L N
ZONE 5
L N
ZONE 6
L N
R W
ZONE 2
R W
ZONE 3
R W
ZONE 4
R W
ZONE 5
R W
ZONE 6
THERMOSTATS
INSOLATED END
SWITCH
X
X ZC ZR
120 VAC
L
N
G
CIRCULATORS
}
To TT
on boiler
Jumper
X
X ZC ZR
ZC
ZR
To ZC on
aquastat
To ZR on
aquastat
GENERAL WIRING DIAGRAM
Refer to Instruction Manual 210688 for units with outdoor reset controller.
Figure 1A: Cold Start Boiler
When a thermostat calls for heat,
the corresponding circulator will
start and the XX end switch will
close to enable the boiler.
Figure 1B: Tankless Coil
When a thermostat calls for heat,
the corresponding circulator will
start when the boiler temperature
reaches the low limit setting.
General Wiring Diagram
(6 zone controller shown)
WARNING: Electrical Shock Hazard
When wiring per the Tankless Coil
Application, pump controller and boiler
aquastat must be on the same circuit and
have a common disconnect. Failure to fol-
low these instructions may introduce a
secondary source of power resulting in
personal injury or death.
4. Make electrical connections according to the applicable
wiring diagram. Run the pump power through the holes in
the controller chassis to the applicable L/N terminals. Keep
120 VAC and 24 VAC wiring separate. All 120 VAC wiring
should be 14 AWG (minimum) copper electrical wire.
Perform all wiring in accordance with applicable codes.
5. If the priority function is to be enabled, the priority zone
(e.g., Domestic Hot Water) pump should be wired to the
Zone 1 L/N terminals.
6. Run the thermostat wires through the grommet(s) in the
controller chassis and connect to the appropriate R/W ter-
minals. If the priority function is to be enabled, the priority
zone (e.g., Domestic Hot Water) T-Stat should be wired to
the Zone 1 R/W terminals. Keep 24 VAC wiring separate
from 120 VAC wiring.
NOTE: During the initial power-up of the zone controller,
some “power stealing” thermostats may require up to 3
minutes to function properly. If the installation requires the
pump relays and X-X relay to be held open during this
power-up sequence, the installer can position DIP switch
6 to the “ON” position. This will cause the controller to
suspend relay operation during the thermostat power-up
period. Normal operation and cycling of the heating system
will resume after the 3 minute time period. This applies to
initial power-up only and does not affect normal system
operation.
EXPANSION
The 4 and 6 zone controllers can be connected together to
accommodate larger systems. A six conductor straight pinned
cable with two male RJ-11 terminations is required for con-
nection of multiple controllers. This cable can be ordered from
your distributor as McDonnell & Miller part number 109454.
The “master” controller should have DIP switch 1 set to the
OFF position. “Slave” controllers should have DIP switch 1 set
to the ON position. If the Priority function is to be enabled
(e.g., domestic hot water production) Zone 1 on the Master
controller will be the priority zone.
Xylem Inc.
8200 N. Austin Avenue
Morton Grove, Illinois 60053
Phone: (847) 966-3700
Fax: (847) 965-8379
www.xyleminc.com/brands/bellgossett
Bell & Gossett is a trademark of Xylem Inc. or one of its subsidiaries.
© 2012 Xylem Inc. 210667C May 2012
