1-33
BOILER SYSTEMS AND OPERATION
DC SERIES BOILERS / WATER HEATERS
DC 15-95, DC 15-96, DC 20-125, DC 33-160
ELECTRICAL CONNECTIONS
All Electrical wiring to the boiler / water heater (including grounding) must
conform to local electrical codes and/or National Electrical Code, ANS/NFPA No.
70 – latest edition, or The Canadian Electrical Code, C22.1 - Part 1.
If an external electrical source is utilized, the boiler, when installed, must be
electrically bonded to ground in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements, with the
National
Electrical Code, ANSI/NFPA 70, and/or the Canadian Electrical Code Part I, CSA
C22.1, Electrical Code.
1.9.1 120VAC Line Voltage Hook-up
Line-voltage wiring is done within the field-wiring box.
(Refer to Section
6.2.Wiring Diagram on page 6-4).
Connect the boiler / water heater to the grid
power using a separate, fused circuit and on/off switch within sight of the boiler /
water heater. Use 14-gauge wire in BX cable or conduit properly anchored to the
boiler / water heater case for mains supply and pump circuits.
The boiler / water heater is equipped with 3 x 1/2" electrical knock-outs located
behind the power supply terminal strip.
Connect the 120 VAC /15 amp power supply to the AC in connections located to
the right side of the controller. To access the terminal strip, remove the boiler /
water heater cover and slide open the controller drawer. Ensure 120 VAC polarity
is correct and that the boiler / water heater is properly grounded.
The DC Series boilers / water heaters include a factory installed and pre-wired
pump. The pump is intended to supply adequate flow for the boiler’s primary
heating circuit only. The system heating pump will need to be switched through a
separate relay or control box.
A second set of contacts is available to connect a DHW pump. This pump will
allow the connection of an indirect fired storage water heater to heating circuit to
take full advantage of the boiler /water heater’s heating capacity. The maximum
amperage rating of the connected pump is 1.0 amps. If the connected pump has
a rating higher than 1.0 amps, an external isolation relay is required to protect the
boiler / water heater’s controller.
A field supplied, external safety device can be connected to the boiler / water
heater by connecting the safety device in series with the boiler / water heater’s
120 VAC power supply. Ensure the external safety device is rated to accept 120
VAC and the total load connected to the boiler / water heater. For an interlock
designed for the sole purpose of protecting the heating circuit of the boiler, the
Auxiliary Safety interlocks can be wired in series with the Call for heat (X4.6 and
X4.7). Do not apply power to the X4 terminal strip. The Auxiliary Safety interlocks
must be a Dry Contact.
1.9
NOTE
The IBC control only
recognizes a true dry contact
closure as a call for heat.
Thermostats and other devices
that use a “Triac” output
cannot be used as a call for
heat without the installation of
an intervening relay with dry
contacts to connect to the IBC
terminal strip.
NOTE
The IBC boiler / water heater
(like any modern appliance that
contains electronic equipment),
must have a “clean” power
supply, and can be disabled
by power surges and spikes,
lightning strikes and other
forms of severe electrical
“noise”. Power conditioning
equipment (surge protectors,
APC or UPS devices) may be
required in areas where power
quality is suspect.
WARNING
Do not apply power to any
connection point on the
controllers terminal strips. A
potentially hazardous situation
could occur which must be
avoided to prevent possible
serious injury or death.
Figure 33: X4 Terminal Strip for connection of the DHW Aquastat (optional), Thermostat or
end switches (mandatory), Outdoor Sensor (optional)
NOTE
A hot water boiler / water
heater installed above radiation
level or as required by the
Authority Having Jurisdiction,
must be provided with a low
water cut-off device at the time
of installation. If a low water
cut-off is not factory installed,
instructions shall be provided
for the installation and wiring
of a low water cut-off.
