COMFORTPOINT PROGRAMMABLE LON, VAV/UNITARY CONTROLLERS
62-0288—03
6
Wiring
All wiring must comply with applicable electrical codes and
ordinances, or as specified on installation wiring diagrams.
Controller wiring is terminated to the screw terminal blocks
located on the top and the bottom of the device.
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or property
damage.
Disconnect power supply before beginning wiring or
making wiring connections, to prevent electrical shock
or equipment damage.
NOTES:
—
For multiple controllers operating from a single
transformer, the same side of the transformer
secondary must be connected to the same power
input terminal in each controller. Controller
configurations will not necessarily be limited to
three devices, but the total power draw, including
accessories, cannot exceed 100 VA when
powered by the same transformer (U.S. only). For
power and wiring recommendations, see “Wiring”.
The earth ground terminal (terminal 3) must be
connected to a verified earth ground for each
controller in the group (see Fig. 12 on page 7).
—
All loads on the controller must be powered by the
same transformer that powers the controller itself.
A controller can use separate transformers for
controller power and output power.
—
Keep the earth ground connection (terminal 3)
wire run as short as possible.
—
Do not connect the universal input COM termi-
nals, analog output COM terminals or the digital
input/output COM terminals to earth ground.
Refer to Fig. 10–Fig. 12 for wiring examples.
The 24 Vac power from an energy limited Class II power
source must be provided to the controller. To conform to Class
II restrictions (U.S. only), the transformer must not be larger
than 100 VA.
Fig. 10 depicts a single controller using one transformer.
IMPORTANT
Power must be off prior to connecting to or removing
connections from the 24 Vac power (24 Vac/24 Vac
COM), earth ground (EGND), and 20 Vdc power (20
Vdc) terminals..
IMPORTANT
Use the heaviest gauge wire available, up to
14 AWG (2.0 sq mm), with a minimum of 18 AWG
(1.0 sq mm), for all power and earth ground wiring.
Screw-type terminal blocks are designed to accept
up to one 14 AWG (2.0 sq mm) conductor or up to
two 18 AWG (1.0 sq mm) conductors. More than two
wires that are 18 AWG (2.0 sq mm) can be con-
nected with a wire nut. Include a pigtail with this wire
group and attach the pigtail to the terminal block.
IMPORTANT
If the controller is used on
Heating and Cooling
Equipment (UL 1995, U.S. only)
and the
transformer primary power is more than 150 volts,
connect terminal 2, (the 24 Vac common [24 VAC
COM] terminal) to earth ground (see Fig. 11). For
these applications,
only one
controller can be
powered by each transformer.
NOTES:
—
Unswitched 24 Vac power wiring can be run in the
same conduit as the L
ON
W
ORKS
® cable.
—
Maintain at least a 3 in. (7.6 cm) separation
between Triac outputs and L
ON
W
ORKS
® wiring
throughout the installation.
Fig. 10. Power wiring details for one controller
per transformer.
Fig. 11. Transformer power wiring details for one
controller used in UL 1995 equipment (U.S. only).
More than one controller can be powered by a single
transformer. Fig. 12 shows power wiring details for multiple
controllers.
CONNECT POWER TO
TERMINALS 1 AND 2
EARTH
GROUND
(TERMINAL 3)
TRANSFORMER
OUTPUT
DEVICE
POWER
M23557A
Δ
P
1 2 3 4 5 6 7 8
1
0
9
2 3 4 5 6 7 8 0
9
1
1 1 1 1 1 1 1 1 2
1
1 2 3 4 5 6 7 8 0
9
2
2 2
2 2 2 2 2 2 3
3
1 2 3 4 5 6 7 8 0
9
3
3
3
3 3
3 3
3 4
COM
24 VAC
M23558A
EARTH
GROUND
(TERMINAL 3)
TRANSFORMER
OUTPUT
DEVICE
POWER
Δ
P
1 2 3 4 5 6 7 8
1
0
9
2 3 4 5 6 7 8 0
9
1
1 1 1 1 1 1 1 1 2
1
1 2 3 4 5 6 7 8 0
9
2
2 2
2 2 2 2 2 2 3
3
1 2 3 4 5 6 7 8 0
9
3
3 3
3 3
3 3
3 4
EARTH
GROUND
1
LINE VOLTAGE
GREATER
THAN 150 VAC
IF THE CONTROLLER IS USED IN UL 1995 EQUIPMENT AND THE
PRIMARY POWER IS MORE THAN 150 VOLTS, GROUND 24 VAC COM
SIDE OF TRANSFORMER SECONDARY.
1
COM
24 VAC
CONNECT POWER TO
TERMINALS 1 AND 2
