Lennox CHA16, Руководство по обслуживанию

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Page 46
1- Disconnect power.Turn thermostat to OFF posi
tion (occupied mode).
2- Install jumper across contactor K3-2 terminals
(see unit diagram) in unit control box. Install jump
er across enthalpy control terminals T and T1.
See figure 51 for terminal location.
3- Restore power to unit. Outdoor damper should
drive to fully open position (60 to 90 sec. required
for full travel). Observe travel for proper damper
operation.
4- Disconnect power to unit. Outdoor damper should
spring return to closed position.
FIGURE 50
REMD16M INSTALLATION
REMD16 GRAVITY
EXHAUST ASSEMBLY
PED16
(IF USED)
ECONOMIZER
FILTERS
REMD16 INTAKE
HOOD
UNIT
FILTERS
VERTICAL
MULLION
SCREWS
ECONOMIZER
CONTROLS
FIGURE 51
MODULATING
SOLID STATE ENTHALPY CONTROL
TR TR1
A
B C
D
+
+
5
2
4
T1
P1 P
T
1
MINIMUM
POSITIONER
LED
3
5- Remove T and T1 jumper then restore power to
unit.Outdoor damper should drive to minimum
position. Adjust minimum damper position pot lo
cated on control.See figure 51.
6- Disconnect power to unit and remove jumper on
blower relay terminals 6-9.Replace all pan
els.Restore power to unit.
D-Transitions
Optional supply/return transition SRT16 is available for use
with CHA16 sries units utilizing optional RMF16 roof mounting
frame.The transition must be installedin the RMF16 mounting
frame before mounting the CHA16 to frame.Refer to the
manufacturer's instructions included with the transition for de
tailed installation procedures.
E-Supply and Return Diffusers
Optional flush mount diffuser/return FD11 and extended
mount diffuser/return RTD11 are available for use with the
CHA16. Refer to manufacturer's instructions included with
transition for detailed installation procedures.
F-Firestats
Some local codes require the installation of discharge air and
return air firestats to automatically shut down the unit when
excessive temperature is reached .Other local codes require
firestats wired to perform tasks such as energizing a blower or
closing dampers.These field provided firestats MUST be
mounted and wired per local codes or insuring agencies.If
manual reset controls are used, they MUST be accessible.
Firestat wiring is shown on the unit wiring digrams in back of
this manual.
G-Cycle Control Kit (Figure 52)
Optional cycle control kit, when applied to CHA16 unit with
electromechanical thermostat, prevents frequent cycling
caused by thermostat diddling or thermostat bulb vibra
tion.The cycle controls require minimum on and minimum off
times before compressors can be energized or deenergi
zed.The cycle controls plugin to the J16/P16 jackplug located
in the control box.No field wiring is required.The kit consists of
two cycle control delays DL8 and DL9.Once installed, DL8
prevents the first stage compressors from being energized
until the first stage thermostat bulb has been closed for at
least 30 seconds. First stage thermostat bulb must be open
for at least 240 seconds before first stage compressors can
be deenergized.DL9 prevents second stage compressors
from being energized until second stage thermostat bulb has
been closed for at least 60 seconds.Second stage thermostat
bulb must be open forat least 240 seconds before second
stage compressors can be deenergized.
NOTELate production CHA16 units are equipped with
factory installed cycle controls.