25
YORK INTERNATIONAL
2
FORM 100.50-NOM1 (604)
AIR HOODS FOR ECONOMIZER
There are three (3) economizer outside air intake hoods
pro vid ed with the unit. The hood on the end of the unit
is factory mounted. The two (2) front and rear hoods are
made operational per the following instructions:
• Remove the screws holding the economizer hood
ship ping covers in place. Discard covers.
• Apply a bead of RTV sealer along the edge of
both hoods and each pivot joint to prevent water
leakage.
• Rotate the hoods out (each hood is hinged). Secure
the hoods with screws along the top and sides.
• Seal any unused screw holes with RTV or by re-
plac ing the screw.
AIR HOODS FOR FIXED OUTSIDE AIR
(UNITS WITHOUT ECONOMIZER)
These hoods are factory installed. The dampers may
be adjusted by loosening the thumb screw, turning the
le ver to the desired position, and retightening the thumb
screw.
AIR HOODS FOR EXHAUST AIR
When furnished, these hoods and dampers are factory
installed.
FIELD WIRING
Figure 7 shows the
Þ
eld control wiring to CTB1 for
both a Con stant Volume and Variable Air Volume units.
All
Þ
eld control wiring is
Þ
eld supplied and installed.
Figure 8 shows
Þ
eld control wiring for FlexSys op tions,
wired to CTB2.
Figure 7 shows CTB1
Þ
eld control wiring.
Thermostat
A thermostat (2 stage cool or 2 stage heat) can be used
for either CV or VAV units. On CV units the thermo-
stat is the primary means of control for he unit. The
thermostat should be mounted on an inside wall ap-
proximately 56" above the
ß
oor where it will not be
subject to drafts, sun exposure or heat from electrical
Þ
xtures or appliances.
Space Sensor
The space sensor (if used) can be used on either CV or
VAV units. The space sensor can be used for unit con trol
in lieu of a thermostat. Even if a thermostat is wired
to the rooftop unit, the space sensor will supply space
air tem per a ture values if connected. When mounting
a space sensor, it should be located on an inside wall
ap prox i mate ly 56" above the
ß
oor where it will not be
sub ject to drafts, sun exposure or heat from elec tri cal
Þ
x tures or appliances.
Shielded Wire must be used
that is grounded at control panel only.
CO
2
Sensor
The optional CO
2
sensor is used for demand ventilation
and must be wired to the
Þ
eld control wiring terminal
block using two-conductor shield wire.
Shielded Wire
must be used.
Occupied/Unoccupied Input
A contact-closure input is provided for hard-wiring an
external device such as a central time clock, a ther mo stat
with scheduling or BAS system, or a manual switch.
Contact Closure = Occupied
Contacts Open = Unoccupied
Note that 24 volts (R), terminal 16, must be used as
the 24 volt AC source for switching the contact to the
unit controller Occupied/Unoccupied input. Use of any
pow er source external to the con trol ler will result in
damage to the unit controller.
Shutdown Input
A contact-closure input is provided for emergency
shut down of the unit. When a contact closure to this
input, the unit shuts down with supply fan, exhaust fan
turned off, and outside air dampers are closed. This
state is maintained until the input is deactivated (con-
tacts open).
Contact Closed = Shutdown
Contacts Open = Normal Operation
Note that 24 volts (R), terminal 16, must be used as the
24 volt AC source for switching the contact to the unit
controller shutdown input. Use of any power source
external to the con trol ler will result in damage to the
unit controller.
