Johnson Controls UNT110-1 Manual page 32

L1 L2
See CAUTION for
Wiring to Unit
Mounted Controls--
UNT110/111 and
UNT120/121 section.
Figure 11: Binary Output Triac Connections on Terminal Strip Versions
32 UNT Controller—Unitary (UNT) Controller
Internal Wiring Connections
COM Z
24
REF N2 N2
- +
VAC BUS
UNT Controller
Triac Switching
24 24 TR-
BI2 BI3 BI4
VAC VAC IAC
COM
24 VAC
Unit Mounted Control Enclosure
Stepdown
Transform er
Fan
Relay
On unit mounted controls, OEMs typically minimize
wiring between digital controls and equipment interface
relays by using one leg of the stepdown transformer
as common.
LOW
BO1 RTN BO2 BO3 RTN BO4 BO5 RTN
B01
Heat Comp.
Relay Relay
wireunt2
of the UNT140/141
Triac
Switching
Jumper
HIGH
Jumper allows
field selection
of the supply leg
to be switched
by the triacs.
In this example,
the triacs' BOs
will switch to
the 24 VAC power
BO6
(high side) leg.
B04
B02
24 VAC
CO MM ON
FAN
HEAT
COMPRESS