Trane Schlage LiNK TZEMT400BB32MAA - Common Wire Installation; Determine 24 VAC Common Wire Requirement; Connect 24 VAC Common Wire

2
3A
If you are unsure about connecting this wire or you do not have any unused wires at the thermostat, contact
Customer Service at (877)288-7707.
Connect a 24 VAC common wire to power the thermostat.
3
Determine if your system has a 24 VAC common wire which is required to power the thermostat.
• If your system is a heat pump, skip to step 4.
a. IfyourexistingthermostathasaterminalnamedC,COM,X,orBwithawireconnectedtoit,skiptostep4.
b. If your thermostat does not have that terminal, or does not have a wire connected to it, go to step 3a.
a. Locate all unused (disconnected) wires from the
thermostat wire bundle and write down the colors.
• i24VCommonwireistypically(notalways)colored
blue
Unused wires
Thermostat
wire bundle
b. GotoyourHVACunitandremovethecover(s)toaccess
the24VACfurnacewireterminals.
24 VAC
Furnace
wire
terminals
Furnace
cover
c. Findthe24VACcommonterminalidentiedwiththe
letter C, X, B, or COM.
• This terminal may already have a wire connected to it
but it may not be a wire that goes to the thermostat
24 VAC common
terminal
(C, X, B, or COM)
G
W
R
C
d. Locate the thermostat wire bundle inside the furnace
panel.
• This wire bundle is routed from the thermostat,
through the walls, and into the furnace panel.
• Thisbundlecanbeidentiedatthefurnaceby
checking the wire colors connected and not connected
and comparing to the wire bundle at the thermostat.
Thermostat
wire bundle
G
W
R
C
Unused
wires
e. Find a wire from the thermostat bundle that is unused at
the thermostat and at the furnace.
• It is possible that one of the unused wires at the
thermostatwillalreadybeconnectedtothe24VAC
commonterminalatthefurnace.Ifso,gotostep4.
G
W
R
C
Unused
wire
f. Connecttheunusedwiretothe24VACterminal,then
replace the furnace cover.
• The24VACcommonwireistypically(butnotalways)
blue in color. If the blue wire has been unused, it is
recommended that you use the blue wire.
G
W
R
C
Connect
wire