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2.6.1 CONSTANT SETPOINT MODE
No external field wiring connections other than
electrical supply connectins are required for this
mode. Although fault monitoring or
enable/disable interlocking wiring can be utilized
(see sections 2.7 and 2.8).
2.6.2 INDOOR/OUTDOOR RESET MODE
This mode of operation increases supply water
temperature as outdoor air temperature
decreases. An Outside Air Temperature Sensor
(AERCO PN 123525 MUST BE wired to the
Field Control Wiring Box using a two wire
shielded cable having a minimum of 22 AWG
(see Fig. 2.11). The cable shield is connected
only at the terminals provided in the field wiring
box. The sensor end of the shield must be left
free and ungrounded. There is no polarity in
terminating the sensor wires. When mounting
the Outdoor Air Temperature Sensor, it should
be mounted on the north side of the building in
an area where the average outside air
temperature is expected. The sensor should be
shielded from sun's direct rays, as well as direct
impingement by the elements. If a cover or
shield is used, it must allow free air circulation.
The sensor may be mounted up to two hundred
feet from the unit.
2.6.3 BOILER MANAGEMENT SYSTEM
MODE
When using multiple units, with an AERCO
Boiler Management System Panel, Model 168,
the field wiring is between the BMS Panel and
each unit's field wiring box (see Fig. 2.11). A
twisted pair of 18 to 22 AWG wire must be
utilized for the connections. No shield is utilized
and polarity must be maintained. The Supply
Header Temperature Sensor (AERCO P/N
122790) must be wired back to the BMS Panel,
regardless of mode of operation. See the
instructions provided with the BMS for proper
location and wiring instructions.
2.6.4 4 to 20 ma REMOTE SETPOINT
MODE
The KC1000 can be controlled with a 4-20 ma
signal from a Building Management System or
an external controller. The supplied 4-20 ma
signal must be a floating (ungrounded) signal.
Connections between the 4-20 ma source and
the unit's field wiring box must be made using a
two wire shielded cable having a minimum
gauge of 22 AWG (see Fig. 2.11). The shield is
connected only at the terminal provided in the
field wiring box. The shield must be left free and
ungrounded at the source end. Polarity must be
maintained when connecting the wires.
2.6.5 COMBINATION MODE
With a Combination Mode unit, field wiring is
between the unit's field wiring box, the CCP
(Combination Control Panel), and the BMS
(Boiler Management System). The wiring must
be done using a shielded twisted pair of 22
gauge wire and polarity must be maintained
between the unit, the CCP, and the BMS.
Control wire shielding should be secured at each
end of the wiring connections to the terminals
provided. For further instructions and wiring
diagrams consult the BMS and CCP instructions
2.7 ENABLE/DISABLE INTERLOCK
Each unit has an enable/disable interlock circuit
located in the field wiring box. This interlock
must be closed,(jumped), to allow the unit to fire.
When the interlock is open, the control panel
Annunciator will display 'INTERLOCK
DISABLED' and the unit will not fire. The unit
comes factory wired with the interlock closed.
Figure 2.11
Field Control Box Wiring
2.8 FAULT RELAY WIRING
The fault relay is a normally open, single pole,
single throw relay, that is energized upon any
fault condition. The relay will remain energized
until the fault is cleared and the CLEAR button is
pushed. The normally open field connections
are shown in Figure 2.11. The relay contacts are
rated for 5 amps at 250 VDC and 5 amps at 30
VDC.
8
INSTALLATION
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