Metasys UNT Series User Manual

UNT Controller—Unitary Controller (UNT) 33
!
CAUTION: Some local electrical codes require the secondary
common of stepdown transformers be connected to
earth ground (typically on units which are powered by
greater than 150 VAC). You may have a maximum of
one single earth ground connection, which must be at
the transformer secondary common, whether one or
multiple controllers are powered by the same
transformer.
wireunt1
BINARY OUTPUTS
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.
L1 L2
Unit Mounted Control Enclosure
See the
Application Examples
section for more information.
UNT Controller
Triac Switching
ZBUS
REF
N2- N2+
COM 24
VAC
COM
24 VAC
LED
Internal Shared Triac Node
COMPRESS
Comp.
Relay
Heat
Relay
Fan
Relay
Jumper allows field selection of the supply leg to
be switched by the triacs. In this example, the
triacs terminal is jumpered to "24 VAC", so the
triacs switch the 24 VAC power (high side) leg.
COMMON
Stepdown
Transformer
FAN
HEAT
24 VAC
See
CAUTION
for
Wiring to Unit
Mounted Controls--
UNT110/111 and
UNT120/121
section.
Internal Wiring Connections
Figure 13: Binary Output Triac Connections on “Quick Connect”
Versions of the UNT110/111 and UNT120/121
Wiring to Unit
Mounted
Controls--
UNT110/111 and
UNT120/121

Metasys UNT Series Specifications

General

Brand	Metasys
Model	UNT Series
Category	Controller
Language	English