35
• In the event of the network cable being severed or com-
munications between master and slaves being lost for
any reason, the slave units will revert to stand alone con-
trol after six minutes without instruction from the master
unit. During this time, the slave units will monitor the
return-air temperature themselves and will make their
own control decisions based upon the last set of transmit-
ter settings received from the master unit.
Network Connection —
The network cable is routed
between controllers and terminated at each unit in the manner
shown in Fig. 38.
NOTE: The cable screen is provided to prevent signals being
imposed on and corrupting the data carried by the 2 cable
cores. The screen must be grounded at only one end for each
unit on the network.
MAINTENANCE
Maintenance Schedule
EVERY 3 MONTHS — Check the air filter condition. Clean
if necessary (see Filter Removal and Cleaning below).
EVERY 6 MONTHS
1. Follow 3-month maintenance schedule in addition to
below steps.
2. Clean condensate tray with biocide suitable for
polystyrene.
3. Clean fascia.
EVERY 12 MONTHS
1. Follow 6-month maintenance schedule in addition to
below steps.
2. Check all electrical connections for security.
3. Check condensate pump operation.
4. Check the heating and cooling action, to ensure proper
operation.
Filter Removal and Cleaning
1. Disconnect power.
2. Unclip the catches along the edge of each grille and allow
them to hang from the fascia by the molded plastic hinges
located along the opposite edge.
3. If desired, the grilles can be removed from the fascia
completely.
4. Slide the filter out of the small plastic retaining clips on
the back of each grille.
5. Gently vacuum clean the filters on a medium vacuum
power.
6. When cleaned, reverse Steps 2-4 to replace the filters.
Recommended Spares —
It is recommended that one
complete set of air filters be kept on hand for use as needed.
DISASSEMBLY PROCEDURE
Fan Removal
1. Unclip the grille catches and remove the grille(s) from the
fascia.
2. For unit sizes 08,12 only:
a. Remove the fascia by loosening the 4 fascia
mounting bolts and then slide the fascia horizon-
tally until it releases from the chassis.
b. Drain the condensate tray by removing the small
black rubber drain plug, catching the condensate
(if any) in a suitable container.
c. Remove the self-tapping screws securing the two
insulated metal condensate tray support channels
and pull the channels away from the condensate
tray.
d. Pull the condensate tray downwards away from the
chassis.
For unit sizes 18-36 only:
Remove the M6 screws from the black plastic inlet ring
and pull the inlet ring downward from the condensate
tray.
3. Remove the electrical panel lid and disconnect the fan
connections from within the electrical panel.
4. Rotate the fan by hand until the 2 M6 nuts are visible
through the fan mounting access holes. Remove the
2 nuts.
5. Rotate the fan 90 degrees until the remaining 2 nuts are
visible and remove while supporting the fan to prevent it
from falling. The fan can now be dropped down from the
unit.
WARNING
When servicing or repairing this equipment, use only
factory-approved service replacement parts. Refer to the
rating plate on the appliance for complete appliance model
number, serial number and company address. Any substitu-
tion of parts or controls not approved by the factory will be
at the owner's risk.
CAUTION
Do not attempt to reuse any mechanical or electrical con-
trollers which have been wet. Replace defective controller.
WARNING
Disconnect power supply before disassembly to prevent
electrical shock and injury from moving parts.
M A S T E R U N I T
S L A V E U N I T 1
R C S 1 S
_
_
R C S 1 S
_
_
R C S 1 S
_
_
S L A V E U N I T 2
TO OTHER UNITS
To next un it S1
To next un it –
Fig. 38 — Master/Slave Network Connection
a42-4046
