Refer to the following accessory instructions for additional
control wiring information.
•
690.50-N1 - Firestat
•
530.11-N10.1 - Status Panel
•
530.25-N1.7 - Low Ambient Kit
•
530.25-N1.8 - Pumpdown Kit
•
530.11-N10.4 - Night Setback Kit
DUCT CONNECTIONS
The supply and return air duct can be connected to the support
angles which are part of the roof curb package. This allows the
installation of the duct work and roof curb before installing the
unit. All duct connections are contained within the roof curb.
Refer to Fig. 14 for duct connection dimensions for the bottom
side-by-side arrangement.
Refer to Form 55.70-N1 for suggested means of installing and
insulating ducts.
When a unit is used with a ceiling plenum return air system,
sound may be transmitted from the unit thru the ceiling to the
conditioned space. For such applications, there must be a
sound absorption chamber installed on the unit return air inlet
as shown in Figure 15. In this way, sound generated by the unit
is absorbed in the chamber and not transmitted to the condi-
tioned space. The chamber may be constructed of fiberglass
duct or metal duct lined with sound absorption material. Ceiling
return grilles should be located a minimum of 12 feet from the
end of the sound chamber. In every installation a return air duct
must be installed to the unit.
FILTERS
All filters being used in these units are 2" thick. Throwaway
filters or 55% efficient bag type filters are available as factory
options. Cleanable filters or 30% efficient throwaway filters are
available as accessories. The cleanable filters have an alumi-
num mesh media that may be cleaned in hot water or steam,
reoiled and reused indefinitely. The 30% and 55% efficient
filters are available to meet specifications for improved air
filtration. Refer to Table 4 for filter sizes and quantities.
FIG. 14 - DUCT CONNECTIONS
Unit
Model
2" Throwaway
2" Cleanable
2" 30%
55% Bag
DSC360
(6) 2 X 20 X 25
(9) 2 X 20 X 20
(4) 12 X 20 X 24
(4) 12 X 24 X 24
DSC480
(6) 2 X 20 X 25
(12) 2 X 20 X 20
(5) 12 X 20 X 24
(5) 12 X 24 X 24
TABLE 4 - FILTER REQUIREMENTS
FIG. 15 - SOUND ABSORPTION CHAMBER
530.25-N3Y
12
Unitary Products Group