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P/N 42-9534 8/08 Copyright 2008 Hydrotherm
KN-SERIES GAS-FIRED DIRECT VENT CAST IRON BOILERS – CONTROL MANUAL
Wiring
5
Power supply (120 VAC)
Connect minimum 14awg copper wire to the power con-
nection. See Figure 4, page 18.
Install a fused service switch, mounted and installed in ac-
cordance with all applicable codes.
Circulator wiring
All circulators operated by the HeatNet control
require a motor starter or relay to handle the
power load of the circulator. Use the output
terminals of the
KN
HeatNet control ONLY to
operate the starter or relay coil.
Boiler circulator
If the boiler circulator is to be controlled by the boiler’s
HeatNet control, power the boiler circulator starter or relay
coil through the terminals provided on J13 (see Figure 4,
page 18).
System circulator
If the system circulator is operated by one of the HeatNet
controls (by the MASTER boiler control for HeatNet multiple
boiler systems), power the boiler circulator starter or relay
coil through the terminals provided on J13 (see Figure 4,
page 18).
Sensor wiring
Factory-installed sensors —
KN
boilers are provided
with a factory-installed supply sensor (boiler outlet water
temperature), connected to the terminals on J10.
Header (SYS/DHW HEADER) sensor is required
— A
header sensor (SYS/DHW HEADER) must be installed in
the system supply piping (or DHW tank) for HeatNet con-
trolled systems.
Connect the header sensor ONLY to the master
boiler
.
Install the header sensor in an immersion well.
Locate the sensor where it will accurately sense the sys-
tem water supply temperature.
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2.
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Connect the sensor leads to the MASTER boiler elec-
trical connection board terminals on J10 as shown in
Figure 5, page 19.
Th e header sensor can be used with a stand-alone boil-
er to allow regulation of a primary/secondary system,
or to control DHW tank temperature.
Outdoor reset application
— To operate with outdoor
reset, purchase and install an optional outdoor sensor.
Mount the sensor such that it is shielded from direct
sunlight if possible and not likely to be covered by snow
drift s or debris.
Connect the outdoor sensor leads to the electrical con-
nection board terminals on J10 as shown in Figure 5,
page 19.
Th e sensor must be connected to the MASTER boiler
for a HeatNet system.
A member boiler could have its own outdoor sensor if it
is to be activated in override mode by closing the Heat
Demand terminals.
Th e outdoor sensor can also be connected to a stand-
alone boiler connection board.
Return water temperature sensor
— Th e return water
temperature sensor is optional, but is needed for some of
the parameter options.
Parameters that require the return water temperature
sensor are DELTA TEMP (under PUMP OPTIONS)
and EXCHGR DELTA (under AUX FUNCTIONS).
Install the sensor in a well in the boiler return piping.
Connect the sensor leads to the electrical connection
board terminals on J10 as shown in Figure 5, page 19.
Each boiler requires a return water temperature sensor
in order to use the DELTA functions.
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