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XP25
Emergency 24VAC System Operation
The
Y
and
O
terminals located on the outdoor control allow the outdoor unit to be cycled ON and OFF using 24VAC inputs. The
outdoor unit will operate at 100% capacity in this configuration.
NOTE -
Defrost operation will not have any indoor discharge air tempering due to the lack of a W1 out terminal.
The following wiring diagrams display the wiring changes needed to switch a full communicating system to a partial
communicating system with the XP25 running in emergency mode (24VAC inputs to outdoor unit).
Communicating Air
Handler or
Furnance
24VAC Thermostat
RSBus
Communicating Air
Handler or
Furnance
iComfort Wi
−
Fi
THERMOSTAT
NOTE 1
C
Y
R
XP25 UNIT
O
XP25 UNIT
NOTES
:
1. Move two wires on both indoor and outdoor controls from terminals
i+
to
Y1
and
i-
to
O
for 24VAC operation on heat pump and indoor unit.
2. Do not disconnect wires from the XP25
R
and
C
terminals, both are required.
3. Cut R to O link on indoor control.
NOTE 2
iComfort Wi-Fi
®
Thermostat
Communicating Air Handler and XP25
XC25
XP25
CUT LINK
DO NOT CUT
NOTE 3
Emergency 24VAC
(Non-Communicating Mode)
Figure 62. Thermostat Communication Mode
