ACCESSORIES (FIELD-INSTALLED)
Three-Phase Electric Heaters are available in several
capacities to provide maximum flexibility. The heater can be
selected to precisely meet the supplemental heating
requirement of the conditioned space.
These heaters are designed for easy field-installation over the
supply air opening of the indoor unit. They have been tested by
Underwriters’ Laboratories and will be shipped with a UL label.
Every heater will be fully protected against excessive current
and temperature by fuses and two high limit thermostats.
Units with Electric Heat will require only one power supply for
both the heating elements and the supply air blower motor, and
the power wiring can be protected by either dual element/time
delay fuses or an inverse time circuit breaker.
Supply Air Plenums and Return Air Grilles (expanded metal)
are available for free-standing indoor units located in the
conditioned space. Both accessories are finished to match the
exterior of the basic unit, and both can be applied with either
vertical or horizontal units. The supply air plenums are fully
insulated and have double-deflection, adjustable grilles.
Base Sections are available to raise vertical indoor units above
the floor. Outdoor air may be introduced through these bases
by cutting an access opening for the outdoor air duct
connection. These bases are finished to match the exterior of
the basic unit. They may have to be insulated in the field for
certain applications.
Decorative Coil Guards can be field installed to enhance
protection of the unit.
Thermostats with either manual or automatic changeover are
available for precise control of the temperature within the
conditioned space. The manual thermostat has a four-position
selector switch - COOL, OFF, HEAT, and EMERGENCY HEAT,
and three stages of control - one stage of cooling and two
stages of heating. The automatic thermostat has a
three-position selector switch - OFF, AUTOMATIC and
EMERGENCY HEAT, and four stages of control - two stages
of cooling and two stages of heating.
Both thermostats have a two-position fan switch, AUTO and
ON to provide intermittent or continuous blower operation.
NOTE:
The automatic changeover thermostat must be used
on units equipped with a field-supplied economizer.
The first cooling stage of the automatic thermostat will
only control the position of the reversing valve; the
system will still operate with only one stage of cooling.
The EMERGENCY HEAT position on the selector
switch and the second stage of heating will only
function on systems with an electric heat accessory.
STATIC RESISTANCES FOR UNIT ACCESSORIES (IWG)
Unit Model
Accessory
CFM
2400
2700
3000
3300
3600
FEH090
ELECTRIC HEAT
10 KW
0.01
0.01
0.01
0.02
0.02
16 KW
0.01
0.02
0.02
0.03
0.04
26 KW
0.03
0.04
0.05
0.06
0.07
36 KW
0.05
0.07
0.08
0.10
0.11
Supply Air Plenum
0.03
0.03
0.04
0.05
0.06
Return Air Grille
0.02
0.03
0.04
0.05
0.06
CFM
3200
3600
4000
4400
4800
FEH120
ELECTRIC HEAT
10 KW
0.02
0.02
0.03
0.03
0.04
16 KW
0.03
0.04
0.05
0.06
0.07
26 KW
0.06
0.07
0.09
0.11
0.13
36 KW
0.09
0.11
0.14
0.17
0.20
Supply Air Plenum
0.05
0.06
0.07
0.08
0.10
Return Air Grille
0.05
0.06
0.07
0.08
0.10
515.41-TG1Y
Unitary Products Group
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