Qmark MWUH Series - Horizontal / Downflow Unit Heaters - Manual (Page 3)

Mounting
1. Remove the mounting bracket from the heating unit by loos-
ening the bracket screws with a wrench and slipping the han-
dle off over the screw heads.
2. Locate a stud in the ceiling and attach the mounting bracket
to the ceiling joist as shown in Figures 4-A or 4-B. Place a
washer on the screw between the bracket and the ceiling to
act as a spacer and screw them into the stud. Tighten the
screws enough to securely hold the heating unit with the air
flow pointed in the proper direction.
3. Lift the heater up and into the mounting bracket. Align the
screws on each side of the heater with the keyhole slots in
the mounting brackets. If the heater is to be tilted, it must be
positioned in the lower keyhole slots (see Figure 5). Tighten
the bracket screws so the unit is securely suspended at the
desired position.
Wiring
1. To connect the power to the heater, simply remove the screw
from the front of the unit. This allows the hinged bottom to
open, providing access to the electrical wiring and connec-
tors. (See Figure 5)
2. Attach the cable connectors to the unit (See Figure 2) and
slide the 10 gauge wire through the cable connector. Pull
enough wire through the connector to work with when mak-
ing the the connections.
NOTE: Wiring compartment volume: 370 in 3 (6063 cm 3 )
3. Connect the wire to the power terminal block located in the
base of the heater (See Figure 6).
NOTE: Unit is 240/208 volts. When wiring a two conductor cable
with ground the white wire must be marked black by adding a piece
of black electrical tape to the wire near the point of connection.
NOTE: To decrease the heat output of the heating unit, see
Adjusting the Heat Output, Table 2 and Wiring Diagram Figure 7.
Adjusting the Heat Output
Heat output can be increased or decreased by switching wires at
the wattage change terminal board. The heater is factory wired
to deliver a heat output of 17,065 BTU per hour. Should your par-
ticular application require less heat output, refer to Table 2
below and change the wires at the wattage change terminal
board as shown in Wiring Diagram Figure 7.
TO PREVENT POSSIBLE ELECTRIC SHOCK, DISCONNECT
POWER TO THE HEATER AT THE MAIN SERVICE BOX
BEFORE ATTEMPTING TO ADJUST THE HEAT OUTPUT OF
THIS UNIT.
3
CEILING JOIST
WASHER
3 / 8 " DIAGONAL
LAG BOLT
BRACKET
CEILING JOIST
WASHER
3 / 8 " DIAGONAL
LAG BOLT
BRACKET
Figure 4-A
Figure 4-B
Single-Screw Mounting
Double-Screw Mounting
Figure 5
REMOVE SCREW TO OPEN DOOR
USE BOTTOM KEYHOLE
SLOTS IF HEATER IS
TO BE TILTED DOWN
BLK
1
2
3
4
5
6
ELEMENT
HI
LIMIT
FAN
CONT.
7
8
9
10
11
12
C D A B
WATTAGE CHANGE
TERMINAL BOARD
GROUND
THERMOSTAT
L1 L2
POWER
TERMINAL
BLOCK
FIELD
WIRING
FAN
ALARM LIGHT MOTOR
RD
YL
BLU
Figure 7 - Wiring Diagram
TABLE 2. HEAT OUTPUT ADJUSTMENTS
MAX
FUSE HEATER MOVE JUMPERS FROM
BTU/HR VOLTS WATTS SIZE AMPS C-D TO A-B
MODEL NO. MWUH5004A
17065 240 5000 30 20.9 None
14215 240 4165 25 17.4 Blue
11365 240 3332 20 13.9 Blue & Yellow
8533 240 2500 15 10.4 Blue, Yellow & Red
12799 208 3750 25 18.0 None
10659 208 3123 20 15.0 Blue
8533 208 2500 15 12.0 Blue & Yellow
6393 208 1874 15 9.0 Blue, Yellow & Red
MODEL NO. MWUH5008A
17065 208 5000 30 24.0 None
14215 208 4165 25 20.0 Blue
11365 208 3332 20 16.0 Blue & Yellow
8533 208 2500 15 12.0 Blue, Yellow & Red
208/240V - MWUH 5004A
208V - MWUH5008A
G
R
E
E
N
(o
r
B
ar
e
C
o
p
p
er
)
W
HI
TE
BLA
CK
L1
L2
BOTTOM
VIEW
POWER
TERMINAL
BLOCK
Figure 6
*
*NOTE: 240/208 volts. When wiring with a two conductor cable
with ground, the white wire must be marked black.