Electrical Connections; Prior To Operation - Modine MDB Série Manuel D'installation Et De Maintenance

installation / Prior to oPeration

electrical connections

WarninG
1. Disconnect power supply before making wiring connections
to prevent electrical shock and equipment damage.
2. If equipped with the Deadfront Disconnect Switch option,
when the switch is in the "OFF" position, supply power
remains energized at the supply power terminal strip
and the top of the dead front disconnect switch. When
providing service on or near these terminals, building
supply power to the unit should be de-energized.
3. All appliances must be wired strictly in accordance
with wiring diagram furnished with the unit. Any wiring
different from the wiring diagram could result in a hazard
to persons and property.
4. Any original factory wiring that requires replacement
must be replaced with wiring material having a temperature
rating of at least 105°C.
5. Ensure that the supply voltage to the appliance, as indicated
on the serial plate, is not 5% greater than rated voltage.
caution
Ensure that the supply voltage to the appliance, as indicated on
the serial plate, is not 5% less than the rated voltage.
1. Installation of wiring must conform with local building
codes, or in the absence of local codes, with the National
Electric Code ANSI/NFPA 70 - Latest Edition. Unit must be
electrically grounded in conformance to this code. In
Canada, wiring must comply with CSA C22.1, Part 1,
Electrical Code.
2. Job specific wiring diagrams are furnished with each unit.
A permanent laminated diagram is located on the inside of
the electric control cabinet door. All units are supplied with
a labeled terminal strip for ease of wiring. Refer to this
diagram for all wiring connections.
3. Make sure all multi-voltage components (motors,
transformers, etc.) are wired in accordance with the power
supply voltage.
4. The power supply to the unit must be protected with a
lockable fused or circuit breaker disconnect switch. If a
disconnect switch is not supplied with the unit, the field
supplied disconnect must have adequate ampacity and
must be installed in accordance with Article 430 of the
National Electric Code, ANSI/NFPA 70.
5. The power supply must be within 5% percent of the voltage
rating and each phase must be balanced within 2 percent
of each other. If not, advise the utility company.
6. External electrical service connections that must be
installed include:
a. Supply power connection (115, 208, 230, 460, or 575
volts).
b. Connection of thermostats, remote monitoring panels,
building pressure sensors, time clocks, or any other
accessory control devices that may be supplied (115
and/or 24 volts - refer to unit wiring diagram).
7. All outdoor electrical connections must be weatherized to
prevent moisture from entering the electrical compartment.
Refer to the unit dimensional drawings on pages 34 through
37 for the electrical knock-out locations.
8. All supply power electrical connections are made in the
electrical section of the unit.
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9. Refer to the wiring diagram for the terminal location of all
wiring.
note: If the unit is not factory supplied with an optional timed
freeze protection (low-temperature system), then a low-
temperature limit control must be field supplied and
installed in areas where freeze protection is needed in
the event of burner shutdown.

Prior to oPeration

Although this unit has been assembled and fire-tested at the
factory, the following pre-operational procedures must be
performed to assure the unit has not been damaged or mis-
aligned during shipment. This will help assure proper on-site
operation.
1. Remove all shipping straps, braces and tie downs.
2. Check burner to insure proper location and alignment.
3. Check blower and motor alignment, as well as belt tension.
4. Check bearings for alignment and tightness. Check bearing
to shaft set screws for tightness.
5. Check all electrical connections for tightness.
6. Check gas piping for leaks using a soap/water solution.
7. Check gas tightness of safety shut-off valve following
procedure below.
test Procedure for checking Gas tightness of safety
shut-off valve
1. While the unit is off, attach a pressure gauge to the
downstream side of the second safety shut off valve
(SSOV) closest to burner.
2. Following normal start-up procedure described in this
manual, allow the burner to go to main flame.
3. Shut the unit off and let the pressure drop to zero.
4. Close hand shut-off valve immediately downstream of the
second SSOV and wait 5 minutes.
5. There should be no changes in pressure. If the pressure
increases, the second SSOV needs to be replaced.
6. Remove the test plug located between the two SSOV's and
let the pressure to drop to zero.
7. Move the pressure gauge to the test port between the two
SSOV's and wait 5 minutes. Make sure to replace the plug
in the test port downstream side of the second SSOV.
8. There should be no changes in pressure. If the pressure
increases, the first SSOV needs to be replaced.
9. Remove the pressure gauge and plug the test port.
10. Open the hand shut-off valve and the unit is ready for
operation.
evaporative cooling units
For units equipped with an evaporative cooler, refer to
Installation and Service Manual - Evaporative Coolers
(Literature 7-569).
After these preliminary checks have been made, the unit can
be prepared for start-up.
Each unit is supplied with this Installation and Service Manual,
which includes a Field Start-Up Form on page 45. The Field
Start-Up Form must be followed and properly filled out by
the installer, with one copy kept with the unit.
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