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Installation
gas heat section. It is extremely important that the
condensate be piped to a proper drain. Refer to the
appropriate illustration in
Figure 26, p. 43
the drain connection.
Note: Units equipped with an optional modulating gas
furnace will likely operate in a condensing mode part
of the time.
Ensure that all condensate drain line installations comply
with applicable building and waste disposal codes.
Note: Installation on gas heat units will require addition of
heat tape to the condensate drain.
Electric Heat Units
Electric heat units operating on 200/230 volts require two
power supplies as illustrated in
unit was ordered with the optional factory mounted, non-
fused disconnect switches, two field-supplied disconnect
switches must be installed per NEC requirements. The
power wires for the electric heat are routed into the electric
heat control panel using the through-the-base access
provided in the heating section. Refer to the unit base
layout for dimensional data. For units operating on 460/575
volts, only one field installed disconnect switch is required.
Use the information provided in the "Power Wire Sizing &
Protection Device Equations," to determine the appropriate
wire size and Maximum Over current Protection for the
heaters/unit.
Note: Each power supply must be protected from short
circuit and ground fault conditions. To comply with
NEC, protection devices must be sized according to
the "Maximum Over current Protection" (MOP) or
"Recommended Dual Element" (RDE) fuse size data
on the unit nameplate.
Provide grounding for the supply power circuit in the
electric heat control box.
Economizer and Relief Air
Damper Adjustment
Relief Air Dampers
Verify that the relief dampers (if equipped) close tightly
when the unit is off.
If relief dampers are not tightly closed with unit off, take the
following steps to preload the dampers:
1. Loosen the relief damper actuator clamp from the
jackshaft
2. From the unit display, command the actuators to 4%
open using the Manual mode. This will cause the
actuators to rotate to approximately 5 degrees.
3. Close the dampers by hand and tighten the actuator
onto the jackshaft
4. Command the dampers to 0%. This will cause the
actuators to rotate back to zero degrees, putting load
48
for the location of
Figure 16, p.
37. Unless the
on the dampers so that they are fully closed at 0%
command.
5. Put the relief damper position back into Auto mode.
Outside Air and Return Air Damper
Operation
The outside air and return air damper linkage is accessible
from the economizer section of the unit. The damper
linkage connecting the outside air dampers to the return air
dampers is preset from the factory in the number 1
position.
WARNING
No Step Surface!
Failure to follow instruction below could result in
death or serious injury.
Do not walk on the sheet metal drain pan. Walking on
the drain pan could cause the supporting metal to
collapse and result in the operator/technician falling.
Note: Bridging between the unit main supports may consist
of multiple 2 x 12 boards or sheet metal grating.
Arbitrarily adjusting the outside air dampers to open fully
when the return air dampers are closed or; failing to
maintain the return air pressure drop with the outside air
dampers when the return air dampers are closed, can
cause building pressurization control problems due to
improper CFM being delivered to the space.
The outside air/return air damper linkage is connected to a
crank arm with a series of holes that allows the installer or
operator to modify the amount of outside air or return air
damper travel in order to balance the pressure drop
between the two air paths.
Adjust the Outside Air Damper Travel
Units with Single Actuators (20 - 55 Ton)
1. Drill a 1/4" hole through the unit casing up stream of the
return air dampers. Use a location that will produce an
accurate reading with the least amount of turbulence –
several locations may be necessary, then average the
reading.
WARNING
Hazardous Voltage!
Failure to disconnect power before servicing could
result in death or serious injury.
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Verify that no power is
present with a voltmeter.
Important: HIGH VOLTAGE IS PRESENT AT
TERMINAL BLOCK OR UNIT
DISCONNECT SWITCH.
2. Close the disconnect switch or circuit protector switch
RT-SVX063G-EN
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