4
7. Each heater has a wiring diagram affixed to the inside of the
access door. Consult this diagram before making any field
connections.
Important Note - Installation Screw lug torque:
During transportation it is possible screw lug connections can
loosen. After installation, before power is turned on to the heater,
check all screw lug connections for tightness to a recommended
minimum torque of 35 in-lbs. (3.9 N-m). Loose connections may
present a hazard.
8. single or three-phase power connections may be used with
heater models MUH0521, MUH0581, MUH072, MUH078,
MUH102, MUH108, and MUH158. These units are factory
wired for single-phase operation. if these heaters are for
use with three-phased power, reconnect the wires as indicat-
ed in the wiring diagram attached to the heater. Additional
information can be found by looking at the wiring illustrations
in figures 3a and 3b and following the directions shown
below.
on models MUH0521,MUH0581, MUH072, MUH078, MUH102,
and MUH108 (figure 3a), move only the two wires marked “A1”
and marked “B1”; do not move or change any other wiring. The
element lead wire marked “B1” which is factory connected to the
power terminal block (terminal located closest to the elements)
must be moved to terminal “B” on the three-phase terminal block.
A
B
LEAD WIRE
"B1"
ELEMENTS
CONTACTOR
(OR P2)
POWER TERMINAL BLOCK
HEATER FRONT
LEAD WIRE
"A1"
3 PHASE BLOCK
T
O
E
L
E
M
E
N
T
S
A
B
LEAD WIRE
"B1"
ELEMENTS
CONTACTOR
(OR P2)
POWER TERMINAL BLOCK
HEATER FRONT
LEAD WIRE
"A1"
3 PHASE BLOCK
T
O
E
L
E
M
E
N
T
S
FACTORY-WIRED FOR SINGLE-PHASE POWER
FIELD-WIRED FOR THREE-PHASE POWER
Figure 3a. Wiring Connections for Single-Phase and three -Phase Power(MUH0521, MUH0581, MUH072, MUH078, MUH102
and MUH108)
B
3 PHASE BLOCK
FACTORY-WIRED FOR SINGLE-PHASE POWER
C1
D
1
D
1
C
1
C
D
B
C
D
3 PHASE BLOCK
B
3 PHASE BLOCK
FIELD-WIRED FOR THREE-PHASE POWER
C1
D
1
D
1
C
1
C
D
B
C
D
3 PHASE BLOCK
Figure 3b. Wiring Connections for Single-Phase and three -Phase Power (MUH158)
Содержание MUH Series
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