Marley MWUH Installation and operating instructions

Model No. MWUH
Horizontal / Vertical Unit Heater
(Field Adjustable from 1.9KW @ 208V to 5KW@ 240V
WARNING
Dear Owner,
Congratulations! Thank you for purchasing this new heater manufactured by a division of Marley
Engineered Products. You have made a wise investment selecting the highest quality product in the heat-
ing industry. Please carefully read the installation and maintenance directions shown in this manual.
You should enjoy years of efficient heating comfort with this product from Marley Engineered Products...
the industry’s leader in design, manufacturing, quality and service.
... The Employees of
Marley Engineered Products
Read Carefully - These instructions are written to help
you prevent difficulties that might arise during installation
of heaters. Studying the instructions first may save you
considerable time and money later. Observe the following
procedures, and cut your installation time to a minimum.
TO REDUCE RISK OF FIRE, ELECTRIC SHOCK OR HEATER FALLING:
1. Use minimum 6 ° copper wire only.
2. Heater air flow must be directed parallel to, or away from,
adjacent walls.
3. Observe wall, floor, and ceiling clearance requirements.
4. All wiring must conform to national and local electrical codes
and the heater must be grounded as a precaution against
possible electrical shock. Heater circuit must be protected
with proper fuses. See Table 1 on page 3.
5. The mounting structure and the anchoring hardware must be
capable of reliably supporting the weight of the heater and, if
used, the mounting bracket.
6. All electrical power must be disconnected at the main service
box before installing, inspecting, cleaning or servicing the
heater. This is a precaution to prevent possible electrical
shock.
7. This heater is not suitable for use in hazardous locations as
defined by the National Fire Protection Association (NFPA).
This heater has hot and arcing (sparking) parts inside. Do not
use in areas where gasoline, paint, or flammable liquids
are used or stored.
8. This heater is not suitable for use in corrosive atmospheres
such as marine, green houses or chemical storage areas.
9. This heater must be mounted at least 6 feet (1829 mm) off the
floor.
1 . This unit only operates on 24 or 2 8 volts (AC), 6 Hz.
Improper installation or failure to follow the procedures out-
lined in this instruction manual can result in serious electrical
shock.
Installation & Maintenance Instructions
SAVE THESE INSTRUCTIONS
!
FILE #E216 9
1

Remember to place a washer on the screws before you insert them
through the holes in the mounting bracket and screw them into the joist.
Tighten the screws enough to securely hold the heating unit with the air
flow pointed in the proper direction.
2. Hanging the Heater
Attach the heating unit to the mounting bracket. Lift the heater up and
into the mounting bracket. The bracket screws, located on each side of
the heating unit, allow the heater to be attached easily to the mounting
bracket by aligning the screws 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 Fig. 4). Tighten the bracket screws with a wrench so
the unit is securely suspended at the desired horizontal or vertical level.
3. Connecting the Power
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 connectors. (See Fig. 4)
Attach the cable connectors to the unit (See Fig. 1) and slide the 1
gauge wire through the cable connector. Pull enough of the wire through
the connector so you will have enough wire to work with when you make
the connections.
NOTE: Wiring compartment volume = 370 in3(6063 cm3)
Connect the wire to the power terminal block located in the base of the
heater (See Fig. 5).
NOTE: To decrease the heat output of the heating unit, see
Table 1 and wiring diagram on page 3.
Turn on the power at the main service.
OPERATION
Setting the Thermostat
INTRODUCTION
Your new heater has unmatched operating flexibility, designed to meet
a variety of heating requirements by simply switching a few easily
accessible wires located in the base of the unit. With heat output rang-
ing from 6,396 to 17, 65 BTU’s per hour, this unique feature lets you
use a single unit to meet a wide range of heating applications.
This manual shows you how to install, operate, and maintain your
MWUH5 4 electric heater.
Hardware Needed
You will need the following hardware for installation:
• Enough 1 ga. min. insulated copper conductor (with ground)
wire to run power from the breaker/ fuse to the heater. Only use
copper wire rated at least 6 ° C. Do not use aluminum wire with
this unit.
• Proper size fuses or circuit breakers in accordance with the
National Electrical Code. Also see Table 1, page 3.
• Wood Screw, 3/8" x 2" (9.5 mm x 5 mm) Lag bolts (Qty. 1 or
2).
• Washer, 3/8" (9.7 mm) (Qty. 2)
• Wire connectors sized to your application.
NOTE: For certain applications, conduit may be required (see Fig.
1). Check local electrical codes. Also, if you run the wiring in con-
duit and wish to be able to turn the heater, be sure to purchase
enough flexible conduit to allow the heater to be turned.
FINDING THE BEST LOCATION
FOR YOUR HEATER
The heater should be installed out of traffic areas and at least 6' off the
floor. The direction of air flow should not be restricted (ie: by columns or
machinery) and the air flow should wipe exposed walls, rather than
blowing directly at them. When more than one heater is used in an area,
the heaters should be arranged so that the air discharge of each heater
supports the air flow of the others to provide best circulation of warm air,
as indicated in figure 2, below.
Mounting Height
See Specifications, page 4.
Distance from Walls
See Specifications, page 4.
1. Mounting the Bracket
Locate a joist in the ceiling and attach the mounting bracket to the ceil-
ing joist as shown in figures 3-A or 3-B. You will need to remove the
mounting bracket from the heating unit by loosening the bracket screws
with a wrench and slipping the handle off over the screw heads.
Connectors, cable, and hardware used to wire the MWUH5004
Figure 1
CEILING JOIST
WASHER
3/8" DIAGONAL
LAG BOLT
BRACKET
CEILING JOIST
WASHER
3/8" DIAGONAL
LAG BOLT
BRACKET
Figure 3-A
Figure 3-B
Single-Screw Mounting
Double-Screw Mounting
Figure 2
Conduit Conduit
Connector
Flexible Conduit Flexible Conduit Connector
Flexible NM Cable Flexible NM Cable Connector
Figure 4
REMOVE SCREW TO OPEN DOOR
USE BOTTOM KEYHOLE
SLOTS IF HEATER IS
TO BE TILTED DOWN
GREEN
(or Bare Copper)
WHITE
BLACK
L1 L2
BOTTOM
VIEW
POWER
TERMINAL
BLOCK
Figure 5
2

Rotate thermostat knob clockwise to high position. After room reaches
desired comfort level, rotate thermostat knob counter-clockwise until the
thermostat clicks off. (Note that the fan delay will keep the fan running
until the elements cool.) Heater will cycle on and off to maintain room
temperature.
NOTE: The first time you operate the unit, it may smoke slightly.
This is due to the residual cleaning agents used to clean the ele-
ment when the heater is manufactured. This is normal and does
not indicate a problem with the unit. This condition will stop after
the heater has been in operation for a few minutes.
Automatic Fan Delay: The MWUH5 4 has an automatic fan delay.
When the thermostat calls for heat, fan action is delayed momentarily
until the heating elements warm. This prevents the circulation of cold air.
When the heater raises the temperature of the room to the thermostat
set point, the heating element is turned off but the fan will continue to run
until the heating element cools down. This prevents exposing the unit to
residual heat, provides a higher comfort level and prolonged element life.
Thermal Cutout: The MWUH5 4 is also equipped with a thermal
cutout which will automatically shut off the heater in the event of over-
heating. The heater will turn on when the operating temperature returns
to normal. Should the unit overheat and activate the thermal cutout
cycle, the cause of the overheating should be determined before further
operation.
NOTE: If the unit is installed in an area where the temperature is
below 50° F, the fan may cycle on and off until the temperature in
the room rises above 50° F, this is normal and does not indicate a
problem with the unit. As soon as the heater warms the air in the
room above 50°, the unit will cycle normally.
Adjusting Air Flow Direction
You can adjust the direction of air flow by:
A. Turning the unit. If the unit has been installed with a single lag bolt,
as shown in the Figure 6, simply turn the entire unit as needed to
adjust air flow.
B. Tilting the unit. Loosen the bracket screws, tilt the heater to the
desired position, and re-tighten the bracket screws (see Figure 4).
NOTE: To tilt the heater it must be mounted in bottom keyhole slots
of mounting bracket to maintain adequate clearance and prevent
possible overheating.
C. Adjusting the louvers to the desired position.
NOTE: The louvers are designed so they can not be complete-
ly closed. Do not attempt to defeat this feature, damage to the
unit can result.
ADJUSTING 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, 65 BTU per hour. Should your particular application
require less heat output, refer to Table 1 and change the wires at the
wattage change terminal board as shown in Wiring Diagram Fig. 7.
MAINTENANCE
Because of its rugged design, superior engineering, and high-quality
craftsmanship, the MWUH5 4 requires little maintenance. With proper
care, your electric heater should last a lifetime, but seasonal cleaning is
recommended to maintain the efficiency of the heater.
Cleaning the Heating Element
To clean the heating element, loosen (but do not remove) the four
Phillips head screws located behind the louvers in the corners of the
louver housing. (See Fig. 8) Grasp the louver housing on both sides, lift
up, and pull out. This provides access to the heating element. Remove
dust or lint with a soft brush or a vacuum cleaner. Replace the louver
housing and tighten the Phillips head screws.
Cleaning the Fan and Motor
Remove the protective grille from the rear of the heater. This provides
access to the fan and motor. Wipe off the fan and motor with a soft cloth
or brush. The fan motor does not require lubrication. Replace protective
grille. (See Fig. 9.)
Figure 6
WARNING
TO PREVENT POSSIBLE ELECTRIC SHOCK, DIS-
CONNECT POWER TO THE HEATER AT THE MAIN
SERVICE BOX BEFORE ATTEMPTING TO ADJUST
THE HEAT OUTPUT OF THIS UNIT.
!
TABLE 1. HEAT OUTPUT ADJUSTMENTS
MAX
FUSE HEATER MOVE JUMPERS FROM
BTU/HR VOLTS WATTS SIZE AMPS C-D TO A-B
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
6396 208 1874 15 9.0 BLUE, YELLOW & RED
TO PREVENT POSSIBLE ELECTRICAL SHOCK, ALL
POWER MUST BE SHUT OFF AT THE MAIN SERVICE
BEFORE INSPECTING OR CLEANING.
BLK
1
2
3
4
5
6ELEMENT
HI
LIMIT
FAN
CONT.
7
8
9
10
11
12
CD AB
WATTAGE CHANGE
TERMINAL BOARD
GROUND
THERMOSTAT
L1 L2
POWER
TERMINAL
BLOCK
FIELD
WIRING
FAN
MOTOR
RD YL
BLU
Figure 7
WARNING
!
CAUTION
USE CARE TO PREVENT DAMAGE TO INTERNAL
HEATER WIRING WHEN CLEANING ELEMENT.
MAKE SURE ALL CONNECTIONS REMAIN TIGHT
AND ALL WIRING IS ROUTED AWAY FROM ELE-
MENT FINS WHEN REASSEMBLING THE UNIT.
ALLOWING WIRING TO TOUCH THE ELEMENT FINS
COULD RESULT IN A FIRE HAZARD.
!
2 8/24 V - MWUH 5 4
3

FAN AND MOTOR
PROTECTIVE GRILL
Figure 9
Mounting Height, ft. (mm) Min. Distance from
BTU per Contactor Vertical Installation Horizontal Installation Horizontal Air Mounting Hole to
Heater Rating and Voltage Hr. Phase Built-in Min. Max. Min. Max. Throw, ft. (mm) Wall, in (mm)
*5000 W @ 240V 17,065
4165W @ 240V 14,215 1 No 6’ 11’ 6’ 8’ 18’ **13”
3332W @ 240V 11,365 (1829) (3353) (1829) (2438) (5472) (330)
2500W @ 240V 8,533
*3750W @ 208V 12,799
3123W @ 208V 10,659 1 No 6’ 11’ 6’ 8’ 18’ **13”
2500W @ 208V 8,533 (1829) (3353) (1829) (2438) (5472) (330)
1874W @ 208V 6,396
*Heater is shipped from factory wired for these wattages. Heater can be field adjusted to the other wattages (Refer to “Adjusting the Heat Output” on page 4.)
**48" (1219 mm) when heater air flow is between 45° downward and vertical.
SPECIFICATIONS
HOW TO ORDER REPAIR PARTS
In order to obtain any needed repair or replacement parts, warranty service
or technical information, please contact Marley Engineered Products Service
Center toll-free by calling 1-8 -642-HEAT.
When ordering repair parts, always give the information listed as follows:
1. The Model Number
2. The Part Description
3. Date of Manufacture
LIMITED WARRANTY
All products manufactured by Marley Engineered Products are warranted against defects in workmanship and materials for one year from date of installation, except
heating elements which are warranted against defects in workmanship and materials for five years from date of installation. This warranty does not apply to damage from
accident, misuse, or alteration; nor where the connected voltage is more than 5% above the nameplate voltage; nor to equipment improperly installed or wired or main-
tained in violation of the product’s installation instructions. All claims for warranty work must be accompanied by proof of the date of installation.
The customer shall be responsible for all costs incurred in the removal or reinstallation of products, including labor costs, and shipping costs incurred to return products
to Marley Engineered Products Service Center. Within the limitations of this warranty, inoperative units should be returned to the nearest Marley authorized service cen-
ter or the Marley Engineered Products Service Center, and we will repair or replace, at our option, at no charge to you with return freight paid by Marley. It is agreed that
such repair or replacement is the exclusive remedy available from Marley Engineered Products.
THE ABOVE WARRANTIES ARE IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR IMPLIED. AND ALL IMPLIED WARRANTIES OF MERCHANTABILITYAND
FITNESS FOR A PARTICULAR PURPOSE WHICH EXCEED THE AFORESAID EXPRESSED WARRANTIES ARE HEREBY DISCLAIMED AND EXCLUDED FROM
THIS AGREEMENT. MARLEY ENGINEERED PRODUCTS SHALL NOT BE LIABLE FOR CONSEQUENTIAL DAMAGES ARISING WITH RESPECT TO THE PROD-
UCT, WHETHER BASED UPON NEGLIGENCE, TORT, STRICT LIABILITY, OR CONTRACT.
Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above exclusion or limitation may not apply to you. This warranty
gives you specific legal rights, and you may also have other rights which vary from state to state.
For the address of your nearest authorized service center, contact Marley Engineered Products in Bennettsville, SC, USA, at 1-8 -642-4328. Merchandise returned to
the factory must be accompanied by a return authorization and service identification tag, both available from Marley Engineered Products. When requesting return autho-
rization, include all catalog numbers shown on the products.
Part No: 52 -2297- SWO 311
7/96
SIDE VIEW
MOUNTING
LOCATION
51/2in.
(165 mm)
1/2in., 3/4in. (2)
(12.7 mm, 19.1 mm)
13/4in.
(44.5mm)
14 in. (356 mm)
121/2in.
(318 mm)
FRONT VIEW
111/4in.
(286 mm)
MINIMUM
DISTANCE
TO WALL
13 in.
(330.2 mm)
Dimension Data
HEATING ELEMENT
Figure 8
SPX Corporation
470 Beauty Spot Rd. East
Bennettsville, SC 29512 USA
4