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Page 52
KN INSTALLATION AND OPERATION INSTRUCTIONS
Appendix A — suggested wiring
(continued)
16
Figure A2 Indoor Air Reset wiring to IAR terminals with
3-wire zone valves and no zone controller
(see Figure 21a for terminal block
6
location)
IAR (Indoor Air Reset) wiring, when used
Wiring for circulator relays (relays must have
24VAC common terminals)
Relays must have a 24VAC common terminal:
The IAR inputs
require a connection to the 24VAC common of the circulator relay to
operate. If the circulator relays do not have a 24VAC common terminal,
you cannot connect to the IAR inputs. To operate with indoor reset,
you will have to remove the existing relays and replace with a circulator
zoning controller or install relays that provide a 24VAC common
terminal.
• Heat Demand terminal connections using circulator relays — The end switch
leads from the relays must connect to the Heat Demand terminals on the electrical
connection board as shown in Figure A2.
• IAR connections — See Figure A1 for typical wiring to the IAR inputs when using
circulator relays. For other applications, see the Control manual and Section 7 of
this manual.
Polarity
— The connections to the
IAR
positive terminals (
IAR +
)
must be as shown in Figure A2. The connections to the
IAR
negative
terminals (
IAR –
) must be from the 24VAC common terminals of the
circulator relays, as shown. Connecting the wires incorrectly can cause
the transformer to be shorted out and damaged.
Verify 24VAC switched lead from thermostat:
Before connecting
the wires to the IAR terminals, use a voltmeter to verify the 24VAC hot
lead is NOT powered when the thermostat is not calling for heat.