Product data

2
Fan
The backward-curved, centrifugal
fans are statically and dynamically
balanced for quiet operation. Fan
impellers are made from either
aluminum or fire-retardant plastic
(UL94 VO) for lightweight and
corrosion-resistant operation. En-
closed multi-speed external rotor fan
motor allows good heat dissipation
and increased motor efficiency. Fans
come complete with thermal over-
load protection and sealed-for-life
lubricated bearings.
Filtration
Reusable wire framed filters are fitted
and may be vacuum cleaned.
Condensate pump
A condensate pump is fitted to carry
water out of the unit. The pump is
fixed to a mounting bracket which
can be withdrawn from the side of
the chassis and incorporates an in-
spection hole to allow a visual check
of the pump during operation. A
float switch is fitted to stop the cool-
ing action should the pump become
blocked or fail.
Air vanes
Air outlet vanes are manufactured
from aluminum and covered with ny-
lon flock to prevent condensation
from forming. Vanes are manually
adjustable on unit sizes 08,12 and
driven by an electric motor on unit
sizes 18-36. Motorized air vanes can
be set to auto sweep or can be
stopped in a fixed position. Polysty-
rene blanking pieces are supplied
with cassette packing so that up to
two fascia discharge slots can be
blanked off.
Alarm interlock relay
Alarm interlock relay includes a relay
for unit failure notification. Normally
open/normally closed contacts are
available for field connection.
Table of contents
Page
Features/Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1,2
Model Number Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Physical Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4,5
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10,11
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Typical Wiring Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Guide Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14,15
Features/Benefits (cont)
Model number nomenclature
42 SERIES HYDRONIC CEILING CASSETTES
20 N
42WKN – Hydronic Cooling
Ceiling Cassette
Supply Voltage
A – 115-1-60
B – 208-1-60
C – 230-1-60
H – 277-1-60
J – 110-1-50
K – 220-1-50
A
Design Revision
A – Current Design
Control
E – Electro-Mechanical Controls
M – Microprocessor Controls
Heating Option
N – None
A – Electric Heat
B – Hot Water Heating Coil
Filtration
A – Cleanable Filter
B – MERV 8 Filter
A E42WKN
Unit Size and Nominal Capacity
08 – 8 MBtuh
12 – 12 MBtuh
18 – 18 MBtuh
20 – 20 MBtuh
33 – 33 MBtuh
36 – 36 MBtuh
A