Duct Installation; Utility Location; Rigging Instructions - Modine MDB Série Manuel D'installation Et De Maintenance

duct installation / utilitY location / riGGinG instructions

duct installation

To assure proper air flow from the discharge of the unit, follow
these recommendations.
1. Be sure properly sized and designed discharge ducts are
installed.
2. Units with twin blowers should have a common discharge
plenum of at least three (3) hydraulic duct diameters.
3. As a general rule, all discharge ducts should have a straight
run of at least three (3) hydraulic duct diameters before
making turns in the ductwork.
For rectangular ducts: dh = 4a/P
For circular ducts: dh = d
where: dh = hydraulic diameter
a = cross sectional area of rectangular duct
P = Perimeter of rectangular duct
d = diameter of round cut
Figure 7.1 shows the recommended duct layout for various
discharge ductwork. Return ducts should be designed in the
same manner.
Where ductwork (or other enclosure) is installed to the inlet or
outlet of the unit in such a way as to cause a possible gas trap
and accumulation of a flammable mixture, a pre-purge cycle
shall be incorporated to provide not less than 4 complete air
changes to the ductwork (or enclosure) by volume prior to an
ignition attempt.
Figure 7.1 - recommended Field-installed
discharge duct configurations
3" MIN.
Provide leak light access panels
in discharge duct for inspection
and service.
TURNING
A
VANES
3"MAX.
AIR
FLOW
MIN. = 3 Hydraulic Duct Dia.
B
3" MIN.
Provide leak light access panels
in discharge duct for inspection
and service.
TURNING
A
VANES
3"MAX.
AIR
FLOW
MIN. = 3 Hydraulic Duct Dia.
B
TURNING
Provide leak light access panels
VANES
in discharge duct for inspection
3"MAX.
and service.
3" MIN.
BAFFLE
A
AIR
FLOW
B
MIN. = 3 Hydraulic Duct Dia.
TURNING
VANES
SIDE VIEW
Dimension "B" should never be
less than 1/2 of dimension "A".
TOP VIEW
SIDE VIEW
Fire dampers
Fire dampers (supplied by others) installed in the inlet or
outlet duct systems shall be provided with electrical interlocks
connected in the safety limit control circuit so as to cause the
heater to shut down in case of fire in the ductwork or unit. The
electrical interlocks must be so arranged that the safety circuit
is electrically energized only when the fire damper is in the
wide-open position.

utilitY location

Electric and control connections can be made either from
the side or the bottom of the unit. The factory-supplied gas
connection is located on the side of the unit. For units without
factory-supplied and mounted disconnects, holes can be cut in
the fixed side panels, or the bottom of the unit. Sealing of holes
cut in the unit casing for utility connections should be done with
care to prevent air and water leaks.

riGGinG instructions

Each unit supplied with four mounting and lifting brackets with
1" clearance holes for lifting hooks.
When units are supplied with factory-mounted accessories,
do not use the accessory lifting eyes to support the load
of the unit. The accessory lifting eyes should only be used to
steady the load. The main load should be placed on the unit's
lifting lugs.
For units with inlet accessories shipped separately, it is
recommended that the unit and accessories be lifted separately
and the accessories assembled to the unit after the unit is put
into place.
The units lifting lugs are supplied at the base of the unit to
provide maximum strength for lifting. in order to lift the unit
without damaging the casing, sPreader Bars must Be
used! Figure 7.2 shows the proper method for lifting the unit
using spreader bars.
Figure 7.2 - typical rooftop rigging
7-500.10
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