80
JOHNSON CONTROLS
5276178-JIM-C-0118
Installation
corner). Secure the hoods with screws along the top
and sides.
Apply a bead of RTV sealer along the edge of both hoods
and each pivot joint to prevent water leakage.
Seal any unused screw holes with RTV or by replacing
the screw.
Air Hoods for Exhaust Air
When furnished, these hoods and dampers are factory
installed.
FIELD WIRING
Figure 26 shows the field control wiring to CTB3. All
field control wiring is field supplied and installed.
Thermostat
A thermostat (2-stage cool or 2-stage heat) can be used
on CV units. On CV units the thermostat is the primary
means of control for the unit. The thermostat should be
mounted on an inside wall approximately 56" above the
floor where it will not be subject to drafts, sun exposure
or heat from electrical fixtures 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 control
in lieu of a thermostat. Even if a thermostat is wired
to the rooftop unit, the space sensor will supply space
air temperature values if connected. When mounting
a space sensor, it should be located on an inside wall
approximately 56" above the floor where it will not be
subject to drafts, sun exposure or heat from electrical
fixtures or appliances.
Shielded Wire must be used
that is grounded at control panel only.
CO
2
Sensor
CO
2
Sensors are required for demand ventilation. The
sensors must be field installed and connected to terminal
block CTB3. One sensor must be installed to sense
outdoor air and one sensor must be installed to sense
indoor air.
Occupied/Unoccupied Input
A contact-closure input is provided for hard-wiring an
external device such as a central time clock, a thermostat
with scheduling or BAS system, or a manual switch.
Contact Closure = Occupied
Contacts Open = Unoccupied
Note that 24V (R), terminal 16 of the terminal block
CTB3, must be used as the 24VAC source for switching
the contact to the Unit Controller Occupied/Unoccupied
input. Use of any power source external to the controller
will result in damage to the Unit Controller.
Shutdown Input
A contact-closure input is provided for emergency
shutdown of the unit. When this circuit is open, 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 activated (contacts closed).
Contact Closed = Normal Operation
Contacts Open = Shutdown
Note that a jumper is installed at the factory between
terminal 16
(R)
and terminal 18 (SD)
of
the low voltage
terminal block CTB3
.
When a field shutdown input
is used, the jumper must be removed and the external
dry contact connected between terminals 16 and 18.
The connection of an external power supply to these
terminals will result in damage to the Unit Controller.
Smoke Purge Input
There is one connection point for Smoke Purge
operation, “Smoke Purge l. When a field supplied dry
contact is closed between terminal 16 (R) and terminal
19 (SMK) the unit will initiate whatever smoke purge
sequence has been programmed into the Unit Controller
for Smoke Purge Sequence 1.
Refer to the SMOKE
PURGE information contained in Section 5 of this
manual for additional programming information
. The
Smoke Purge operating state will be maintained until
the contact is opened.
No external power source may be
used when field wiring any of the
above inputs. The 24VAC source on
terminal 2 and 16 (R) of the Terminal
Block CTB3 must be used as the power
source when field wiring these inputs,
Содержание 40 25 TON
Страница 22: ...22 JOHNSON CONTROLS 5276178 JIM C 0118 THIS PAGE INTENTIONALLY LEFT BLANK ...
Страница 35: ...35 2 JOHNSON CONTROLS 5276178 JIM C 0118 FIGURE 10 PARTIAL ROOF CURB MODEL 1RC0455P LD14177 ...
Страница 41: ...41 2 JOHNSON CONTROLS 5276178 JIM C 0118 FIGURE 18 40 TON FORWARD CURVE EXAMPLE ...
Страница 159: ...159 JOHNSON CONTROLS 5276178 JIM C 0118 THIS PAGE INTENTIONALLY LEFT BLANK ...
Страница 244: ...244 JOHNSON CONTROLS 5276178 JIM C 0118 Service NOTES ...