25
Single Point Boxes and Supplementary Fuses
When the unit MOCP device value exceeds 60A, 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 in-
stalled 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 ac-
cess cover. See Fig. 33.
Fig. 33 — Typical Single Point Installation
On 50KCQ units, all fuses are 60A. Single point boxes con-
taining fuses for 208/230-v applications use UL Class RK5
250-v fuses (Bussman FRNR 60 or Shawmut TR 60R). Single
point boxes for 460-v and 575-v applications use UL Class T
600-v fuses (Bussman JJS 60 or Shawmut A6T 60). (Note that
all heaters are qualified for use with a 60A fuse, regardless of
actual heater ampacity, so only 60A fuses are necessary.)
Safety Devices
Electric heater applications use a combination of line-break/
auto-reset limit switches and a pilot-circuit/manual reset limit
switch to protect the unit against over-temperature situations.
Line-break/auto-reset limit switches are mounted on the base
plate of each heater module. See Fig. 34. These are accessed
through the indoor access panel. Remove the switch by remov-
ing two screws into the base plate and extracting the existing
switch.
Pilot-circuit/manual reset limit switch is located in the side
plate of the indoor (supply) fan housing. See Fig. 31 and 34.
Completing Heater Installation
FIELD POWER CONNECTIONS
Tap conductors must be installed between the base unit’s field
power connection lugs and the single point box (with or with-
out fuses). See Fig. 33 and refer to unit wiring schematic. Use
copper wire only. For connection using the single point box
without fuses, connect the field power supply conductors to the
heater power leads and the field-supplied tap conductors inside
the single point box. Use UL approved pressure connectors
(field-supplied) for these splice joints.
Fig. 34 — Typical Location of Heater Limit Switches
(3-phase heater shown)
LOW-VOLTAGE CONTROL CONNECTIONS
Pull the low-voltage control leads from the heater module(s).
The 50KCQ units use a various number of control wires, colors
and terminal boards depending on voltage and unit size. See
Fig. 35-38 and the unit wiring diagram for proper placement.
Fig. 35 — Accessory Electric Heater Control
Connections (HP-2, Size 06, 575-v Only)
Table 10 — Heater Model Number
Bare heater
model number
C
R
H
E
A
T
E
R
0
0
1
A
0
0
Heater Sale Package PNO
Includes:
Bare Heater
Carton and packing materials
Installation sheet
C
R
H
E
A
T
E
R
1
0
1
A
0
0
ALLIED
PA
MO
D
ELN
O.
ERI
ALN
O.
C
O
R
P
.
11
1
3
21
2
3
O
D
22.2
3
1
2
3
I
S
TED
AIR
NDITIONING
UIP
ACCE
SS
3
46N.
P/ N
2--5610
- - 4
REV
111
3
212
3
SINGLE
POINT
BOX
FIELD POWER
CONNECTIONS
HINGED
COVER
ALLIEDPA
MOD
ELN
O.
ERIA
LNO.
C
O
R
P
.
11
1
3
21
2
3
OD
22.2
3
1
2
3
I
S
TED
AIR
NDITIONING
UIP
ACCE
SS
3
46N.
P/ N
2-- 5610
4
-- REV
PILOT --- CIRCUIT/MANUAL
RESET LIMIT SWITCH
LINE--- BREAK
LIMIT SWITCHES
Summary of Contents for WeatherMaker 50KCQ A04 Series
Page 34: ...34 Fig 53 RTU Open Overlay for Economizer Wiring ...
Page 35: ...35 Fig 54 VFD Overlay for W2770 Controller Wiring ...
Page 70: ...70 Fig C 50KCQ A04 A05 A06 Control Wiring Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 71: ...71 Fig D 50KCQ A04 A05 A06 Power Wiring Diagram 208 230 1 60 APPENDIX D WIRING DIAGRAMS ...
Page 72: ...72 Fig E 50KCQ A04 A05 A06 Power Wiring Diagram 208 230 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 73: ...73 Fig F 50KCQ A04 A05 A06 Power Wiring Diagram 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 74: ...74 Fig G 50KCQ A04 A05 A06 Power Wiring Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 75: ...75 Fig H 50KCQ Premier Link Control Diagram APPENDIX D WIRING DIAGRAMS ...
Page 76: ...76 Fig I 50KCQ RTU Open Control Diagram APPENDIX D WIRING DIAGRAMS ...
