Modine Manufacturing GLW, GLW660S, GLW330S, GLW660, GLW330 Service Manual

March, 2002

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1. Inspect unit upon arrival. In case of damage, report
immediately to transportation company and your local
Modine sales representative.

2. Check rating plate on unit and motor to verify that power
supply and motor specification requirements meet
available electric power at the point of installation.

3. Inspect unit received for conformance with description of
product ordered (including specifications where
applicable).

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The heat exchanger is warranted for operation at hot water
pressures up to 300 lbs. per sq. in. gauge, and/or
temperatures up to 180°F.

SSppeecciiaall PPrreeccaauuttiioonnss

1. Disconnect power supply before making wiring
connections to prevent electrical shock and equipment
damage. All units must be wired strictly in accordance
with wiring diagram furnished with unit.

2. Units should not be installed in atmospheres where
corrosive fumes or sprays are present.

3. Units with power codes 01, 02, 03, 04, or 05 must not
be installed in potentially explosive or flammable
atmospheres.

4. Be sure no obstructions block air intake or air discharge
of unit.

LLooccaattiinngg GGLLWW UUnniittss

In locating units consider the general heating and ventilating
requirements of the greenhouse. Arranging units to simplify
piping and electrical supply systems should also be given
consideration.

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Because of their weight it is generally not feasible to
suspend a GLW unit from the roof supports of a
greenhouse. No provision for overhead suspension is
provided on GLW660S units. Brackets to facilitate overhead
suspension of model GLW330S units can be provided.
Normal practice is to place this GLW unit on a field
fabricated stand or platform that is fastened to the floor. Be
sure the means of support is adequate to suppor t the weight
of the unit. For proper operation the unit must be installed in
a level horizontal position.

MMOODDEELL GGLLWW666600SS

PPiippiinngg

Proper operation of the GLW greenhouse heating unit is
dependent on correct arrangement of unit piping.The points
listed below generally outline the areas which must be
considered. For more complete coverage on the subject of
piping, reference should be made to a reputable engineer’s
handbook or the ASHRAE guide.

1. Piping should be sized to properly handle the required
flow (GPM) of water.

2. In the absence of engineered data on an individual
application, piping the full size of the GLW unit
connections should be used. Supply and return runouts
must be the same size.The inlet is on the bottom. Inlet
and outlet connections are clearly marked on each GLW
unit.

3. Air must be continuously eliminated from the GLW unit
to secure rated performance and avoid premature coil
failure.

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All wiring must be done in accordance with the National
Electric Code and applicable local codes. In Canada, wiring
must conform to the Canadian Electric Code. Power supply

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As Modine Manufacturing Company has a continuous
product improvement program, it reserves the right to

change design and specifications without notice.

CAUTION

Disconnect power supply before making wiring
connections to prevent electrical shock and equipment
damage. All units must be wired strictly in accordance
with wiring diagram furnished with this unit.

22

IINNSSTTAALLLLAATTIIOONN//OOPPEERRAATTIIOONN

to these unit heaters must be protected by a fused disconnect
switch. It is recommended that all wiring be adequately
grounded.

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Electric wiring must be sized to carry the full load amp draw of
the motor, starter, and any controls that are used with the unit
heater.All units with power codes 04, 05, 08, or 09 (polyphase
motors) must be provided with suitable overcurrent protection
in circuit supplying heater at installation. Overcurrent
protectors should be sized based on motor current rating
shown on motor rating plate, and applicable national electric
code procedures.

All units are provided with electrical junction boxes.The
GLW660 may be field wired from either junction box.Any
damage to or failure of Modine units caused by incorrect
wiring of the units is not covered by Modine’s standard
warranty.See Page 4.

PPrriioorr ttoo OOppeerraattiioonn

1. Make sure fuses are installed in fused disconnect
switches.

2. Check all electrical connections to assure they are secure.

3. Check rigidity of unit mounting.Tighten all fasteners, if
necessary.

4. Inspect piping, strainers, fittings, etc.

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1. Set thermostat to lowest position.

2. Turn on power supply to unit.

3. Open return gate valve, and then open supply gate valve
to unit.

4. Raise thermostat setting to desired position.

5. To insure proper sequence of operation, cycle unit on and
off a few times by raising and lowering thermostat setting.

6. Check for proper rotation of fan. All fans must rotate in a
counter-clockwise direction when viewed from the back of
the GLW unit.Do not attach polytubes to GLW unit until
proper rotation of fans is assured.

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TTuubbee IInnssttaallllaattiioonn
The polyethylene tube providing air distribution throughout the

greenhouse, is simply and directly connected to the heater
outlet transition with a gasket and a clamp.The clamp and
gasket are shipped attached to the unit.To install:

1. Remove clamp.

2. Thread a tube end through the clamp about 2 to 4 inches.

3. Orient the tube so that the distribution holes are in the
desired position.

4. Fit tube end clamp over the gasketed outlet transition and
secure clamp with a screwdriver.

5. Unroll tube to length desired and tie up opposite end.

6. Add air distribution holes as needed if polytube has been
shortened from standard length.

7. A minimum number of 100-3" diameter holes are required
for a 24" diameter polytube.

TTuubbee SSuussppeennssiioonn
For optimum air distribution the tube should be suspended

about 7 to 9 feet above the floor with the hoops and key rings
supplied.The tube must be hung without sharp bends or
twists.The hoops supplied are special straps of cross­laminated plastic for durability that include eyelets at each end
for clipping into key ring.The key rings, with strap and tube,
may be clipped onto either a long lead wire or an eyebolt in
the truss construction of the greenhouse. Because of the
variety of greenhouse constructions, no further provisions for
suspension are provided other than the hoops and key rings.

Recommended tube suspension with hoops is approximately
eight feet apart, which will be adequate for polytube weight
(12 lbs. per 100 feet) and sufficient to dampen out snapping
action when the tube is initially inflated. For wire suspension,
make sure the key rings are properly anchored, i.e., either
tied, taped, or looped into the wire to prevent shifting.While
the tube is inflated, stretch tube slightly and tie end to
greenhouse frame.This will reduce the chance of tube flutter
and increase the life of the tube.

RReeppllaacceemmeenntt PPaarrttss

All replacement parts and controls are proprietar y in that all
have been designed, tested, and approved for the particular
application to insure both physical and electrical fit and
performance. Any substitution of parts or controls not
approved by Modine will be at customer’s risk.

NNOOTTEE::

Modine Manufacturing Company reserves the right

to substitute parts of advanced design and to
change specifications or prices without advance
notice or without incurring obligations.

Replacement parts can be obtained by submitting the model
number, power code control code and serial number shown on
the rating plate attached to the unit, along with a description of
the part, to the Service Dept., Modine Manufacturing
Company, West Kingston, Rhode Island 02892.