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h) Connect the thermostat or the zone valve end switch wires to "C" and "W1" terminals on the
electronic board. Power stealing thermostats require an isolation relay (not included) and should not be
powered by the W1 and C terminals.
i) Circulating Pump Control. The "P / P" terminals are connected to dry contacts of a relay (capacity up
to 1 HP) and are used to start the pump. This relay is switched ON with the fi rst heating step and OFF
after the last one. A separate 120V / 1Ø service must be provided from the electrical panel to the boiler
for the pump. For Electric Boiler only systems, refer to the wiring diagram. For Electric Boiler with fossil
fuel backup, see the diagram on page 23 labeled 'PUMP WIRING WITH FOSSIL FUEL BACKUP
BOILER' as the pump must also run when another source of heat is selected. Follow the extra steps
dedicated to a FFB installation in the start-up sequence.
j) If the system is used with Load Management control, connect the Utility signal to "S1 / S2" terminals. A
closed contact enables the boiler, an open contact disables the boiler.
k) The installation is now ready for start-up procedure and testing.
Extra test steps for Electric with Fossil Fuel Backup Boiler installation
a) Disconnect the room thermostat wires from the existing boiler and connect them to "C" and "W1"
terminals on the electronic board of the electric boiler.
b) Connect two (2) wires from "B / B" control terminals of the electronic board on the electric boiler to
the T T (thermostat) terminals of the existing boiler.
c) Terminals "S1 / S2" on the electronic board should receive the utility Load Management Control
wires.
d) Connect the pump terminals "P / P" in parallel to the existing thermostatic pump control as per wiring
diagram on page 23 to allow the operation of the pump in any of the "Dual-Energy" modes selected.
e) When the system is opperating in Fossil Fuel mode, the supply water temperature of the fossil fuel
boiler should never exceed 190°F which may trip the manual high limit in the electric boiler.
V.
Sequence of operations
1)
FFB Model sequence of operations:
a)
Power wires connected to circuit breaker(s), control wires connected to C/W1 (thermostat,
aqua stat, zone valve or end switches), load management relay or jumper connected to S1/S2, outdoor
sensor connected to OT/OT. If installed with a gas back-up boiler, wire BB terminals on electric boiler
to TT terminals on back-up boiler.
b)
Boiler is supplied with a three position switch factory set to Dual Energy. In this position, with
S1/S2 closed and a call for heat to C/W1, electric boiler will start. When set to Oil/Gas, with a call for
heat, back-up boiler will start. Middle position is also Dual Energy. A green pilot light indicates the
mode that has been selected.
c)
Breakers turned on at boiler. When Feeder 1 is turned on, transformer is powered. As long as
the fuse is good and the hi-limit has not been tripped, the back-up contactor will energize and close/pull
in.
d)
Call for heat: C/W1 is closed, monitor light will fl ash (upper left hand corner of PC board); the
board will energize the pump relay and close the P.P. terminals switching on the pump. First element
relay LED on board will light (bottom LED next to wiring harness on left side of PC board), indicating
that 24VDC is sent to coil of fi rst element relay (SSR), contact of relay will close and start fi rst element.
e)
After 30 seconds, if boiler has not reached temperature set on aqua stat, second element relay
LED on board will light (second from bottom LED next to wiring harness on left side of PC board)
indicating that 24VDC is sent to coil of second element relay (DC relay), contact of relay will close and
start second element.
f)
Depending on the size of the boiler and number of elements in the tank, the board may energize
the second, third and fourth element relays.
g)
Once temperature set on aqua stat has been achieved, board will control water temperature by
modulation. First element relay will be pulsed on and off and remaining elements will be turned off or
on 100% to maintain the desired supply water temperature.
Page 10
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