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10.
Special Equipment Configurations
10.1. Thermal Protection Switches (S5, S8,
S31 and S180)
NOTE:
Not all models use all of the reference switches.
Verify with unit wiring diagram to confirm switch(es)
used. Also refer the unit installation instruction for
switches used and operation.
Thermal protection switches open on a temperature rise
to de-energize the corresponding compressor. Switches
automatically reset when temperature drops.
The corresponding compressor is locked out after three
occurrences (default) of either high pressure or high
temperature conditions during a demand cycle. The number
of occurrences can be changed using for Parameter 98.
Adjustable range is 1 to 7 occurrences.
On certain compressors, these switches are in series with
the high pressure switches, and will cause a 300 second
delay (default) which is set using Parameter 110. This will
also set off an alarm. Adjustable delay range is 64 to 1800
seconds.
Go to SETTINGS > RTU OPTION > COOLING > 98 (MAX
HP OCCURRENCES)
Go to SETTINGS > RTU OPTION > COOLING > 110 (ERR
TIME OFF DELAY)
NOTE:
Thermal protection switch alarms will not indicate
an OFF ON ALARM state.
3 to 6-ton sizes
has a thermal protection switch
connected to S5. When the compressor is de-energized due
to an open thermal switch, alarm 192 is issued. When the
compressor is locked out after three occurrences, alarm 193
is issued.
10.2. blower Operation with Effective
Occupancy
This section describes how network occupancy signals are
combined to produce effective occupancy.
The blower runs to service heat and cool demands,
regardless of the space occupancy. However when there is
no heating or cooling demand there are options for how the
blower should operate in conjunction with occupancy signals
to keep the space ventilated, or the air stirred.
a. California Energy Commission Title 24
- The legacy
option settings for OCC Blower Mode are AUTO
CYCLES or ON-CONTINUOUS 1. These settings govern
whether the blower runs continuously when the space is
considered occupied, or cycles on/off with the heating
and cooling demand.
To comply with the California Energy Commission Title 24
standard there are two additional values for OCC Blower Mode
which are ON-CONTINUOUS 2 and ON-CONTINUOUS
3. See “Table 4. Blower Operation Description” for their
descriptions.
b.
LonTalk, BACnet and L Connection: These two new
options are available when using these networks types
that supplies a room occupancy signal (in addition to the
scheduled occupancy).
NOTE:
For L Connection the same two options are also
available when using an optional room occupancy
sensor. If a room occupancy sensor is not physically
installed and configured for the network, then the
only options available for OCC Blower Mode are
AUTO CYCLES or ON-CONTINUOUS 1.
c.
RTU Standalone: Since a room occupancy sensor cannot
be used in this configuration, then the only options for OCC
Blower Mode are AUTO CYCLES or ON-CONTINUOUS
1.
d.
Enabling Network Type
To enable the network module, go to
SETUP > INSTALL
and run the setup wizard. When Configuration ID 1 appears
on the screen, configure position 5 to one of the applicable
network types. N = Not Installed, B = BACnet and L =
LonTalk.
e.
Menu Setup Procedure Method for OCC Blower Mode
These blower control options are handled by the OCC
Blower Mode. These setting and be changed using the
following menu path:
Go to
SETUP > NETWORK INTEGRATION > NETWORK
SETUP WIZARD
. Depending on how Configuration ID
1, position 5 is set, different network types will be listed.
Additional prompts concerning network configuration and
sensor types will be asked)
CONTROL MODE = ROOM
SENSOR > ROOM SENSOR OCC bLOWER MODE
=
“Table 4. Blower Operation Description”
Table 4. blower Operation Description
OCC blower Mode
Description
AUTO CYCLES
Blower cycles on/off with demand.
(Legacy usage.)
ON-CONTINUOUS 1
Blower runs when either the
occupancy sensor or schedule, or
both, indicates occupied. (Legacy
usage.)
ON-CONTINUOUS 2
Blower runs when both the
occupancy sensor and schedule
indicate occupied.
ON-CONTINUOUS 3
The same as option 2, but blower
runs for 30 minutes and is off
for 90 minutes when schedule
is occupied but the occupancy
sensor is not occupied.
Table 5. bACnet Occupancy Objects
Input
bACnet
Value
Manual
Occupancy Override
Control
AO 103
0: space occupied
1: space unoccupied
2: refresh space
occupied override
timer
3 255: auto; clear
timer and return to
scheduler
Schedule
Occupancy Scheduler
Control
AO 104
0: space occupied
1- 255: space
unoccupied
Sensor
Occupancy Sensor
Input
AO 107
0: space occupied
1: space unoccupied
2 -255: auto; return to
occupancy scheduler
state
Effective
Occupancy
Effective Occupancy
AI 241
0: space occupied
1: space unoccupied
2: space occupied
(timed override)
