19
SINGLE POINT BOXES AND SUPPLEMENTARY
FUSES
When the unit MOCP device value exceeds 60-A, unit-
mounted supplementary fuses are required for each heater
circuit. These fuses are included in accessory single point
boxes, with power distribution and fuse blocks. The single
point box will be installed directly under the unit control box,
just to the left of the partition separating the indoor section
(with electric heaters) from the outdoor section. The single
point box has a hinged access cover. See Fig. 32. The single
point box also includes a set of power taps and pigtails to
complete the wiring between the single point box and the
unit’s main control box terminals. Refer to the accessory
heater and single point box installation instructions for details
on tap connections.
All fuses on 50KC units are 60-A. (Note that all heaters are
qualified for use with a 60-A fuse, regardless of actual heater
ampacity, so only 60-A fuses are necessary.)
SINGLE POINT BOXES WITHOUT FUSES
Unit heater applications not requiring supplemental fuses re-
quire a special single point box without any fuses. The acces-
sory single point boxes contain a set of power taps and pig-
tails to complete the wiring between the single point box and
the unit’s main control box terminals. Refer to accessory
heater and single point box installation instructions for details
on tap connections.
Fig. 32 — Typical Single Point Installation
LOW-VOLTAGE CONTROL CONNECTIONS
Pull the low-voltage control leads from the heater module(s)
— VIO and BRN (two of each if two modules are installed;
identify for Module #1) — to the 4-pole terminal board TB4
located on the heater bulkhead to the left of Heater #1. Con-
nect the VIO lead from Heater #1 to terminal TB4-1. For 2-
stage heating, connect the VIO lead from Heater #2 to termi-
nal TB4-2. For 1-stage heating with 2 heater modules connect
the VIO lead from both Heater #1 and #2 to terminal TB4-1.
Connect both BRN leads to terminal TB4-3. See Fig. 33.
Fig. 33 — Accessory Electric Heater Control
Connections
Humidi-MiZer
®
Control Connections
HUMIDI-MIZER – SPACE RH CONTROLLER
NOTE: The Humidi-MiZer is a factory-installed option. Hu-
midi-MiZer is not available for size 04-06 single phase (-3
voltage code) models.
The Humidi-MiZer dehumidification system requires a field-
supplied and field-installed space relative humidity control
device. This device may be a separate humidistat control
(contact closes on rise in space RH above control setpoint) or
a combination thermostat-humidistat control device such as
Carrier’s Edge
®
Pro Thermidistat with isolated contact set for
dehumidification control. The humidistat is normally used in
applications where a temperature control is already provided
(units with PremierLink control).
To connect the Carrier humidistat (HL38MG029):
1. Route the humidistat 2-conductor cable (field-supplied)
through the hole provided in the unit corner post.
2. Feed wires through the raceway built into the corner post
(see Fig. 28) to the 24-v barrier located on the left side of
the control box. The raceway provides the UL-required
clearance between high-voltage and low-voltage wiring.
3. Use wire nuts to connect humidistat cable to two PINK
leads in the low-voltage wiring as shown in Fig. 36.
To connect the Thermidistat device (33CS2PPRH-01):
1. Route the Thermidistat multi-conductor thermostat cable
(field-supplied) through the hole provided in the unit cor-
ner post.
2. Feed wires through the raceway built into the corner post
(see Fig. 28) to the 24-v barrier located on the left side of
the control box. The raceway provides the UL-required
clearance between high-voltage and low-voltage wiring.
3. The Thermidistat has dry contacts at terminals D1 and
D2 for dehumidification operation (see Fig. 37). The dry
contacts must be wired between CTB terminal R and the
PINK lead to the LTLO switch with field-supplied wire
nuts. Refer to the installation instructions included with
the Carrier Edge Thermidistat device for more informa-
tion.
AL
LIED
P
A
M
O
DE
L
NO
.
ER
I
A
L
N
O.
C
O
R
P
.
11
13
21
23
O
D
2
2
.
2
3
1
2
3
ISTED
AIR
NDITIONING
UIP
ACCESS
346N
.
P
/ N
2-
5
6
1
0-
4
REV
1
1
13
2
1
2
3
CONTROL
BOX
BUSHING
SINGLE
POINT BOX
MOUNTING
SCREWS
FOAM
BUSHING
DRIP BOOT
BRACKET
MOUNTING
SCREWS
HEATER
RELAYS
POWER
WIRES
HEATER
MOUNTING
SCREWS
HR1: On Heater 1 in Position #1
HR2: On Heater 2 in Position #2 (if installed)
2
3
12
13
2
TB4
HR2
HR1
Elec Htr
CONTL
BOARD
CTB
Field
Connections
VIO BRN BRNVIO
VIO BRN
VIO BRN
ORN
BRN
VIO
ORN VIO BRN
To Next Page
Loading...
