Table of Contents
Advertisement
circumstances, allowing the brownout to be ignored for
a time period should not be needed. The 8201-169 is
shipped with all the DIP switches in the 'off' or 'do not
ignore' position (see Figure 39).
If ignoring the brownout is needed because of the
above conditions, three preset timers can be set by DIP
switches in order to delay signaling a power brownout
for a specific length of time after compressor contactor
is energized. This allows the compressor a time period
to start even if the voltage has dropped and allows
the voltage to recover. This delay only happens when
the CC terminal energizes. The delay can be set to 1
second (A DIP switch), 5 seconds (B DIP switch) or 10
seconds (C DIP switch); time is not cumulative—only
the longest setting will apply. If the voltage recovers
during the brownout delay period, the compressor will
start.
If a brownout condition is detected by the 8201-169,
the troubleshooting light will flash blue. The light will
continue to flash until the cooling call is satisfied or
power is removed from the Y terminal. This condition
does not prevent operation, it only indicates that a
brownout condition was present at some point during
the cooling call. If a brownout condition is detected,
CC will be de-energized and will retry after the delay-
on-make timer is satisfied; this process will continue
until call is satisfied.
If user chooses the 'do not ignore' position when the
site has inadequate utility or generator power, this
could lead to the compressor never starting. The
control will see the brownout immediately and not start.
A common scenario and one that has been seen in the
field is when a unit or units switches from utility power
to generator power. With slower transfer switches, the
time delay between the utility power and generator
power didn't cause a problem. The units lost power,
shut off and came back on line normally. With the
introduction of almost instantaneous transfer switches,
the millisecond long power glitch can be enough that
the compressor will start to run backwards. In this
scenario, the CCM will catch this and restart the units
normally.
High Pressure Safety Switch
All units have a high pressure switch as a safety device.
This device will open when pressure in the system
reaches 650 PSIG. The sensor is directly connected
to the dedicated compressor control module (see High
Pressure Detection on page 26).
Refrigerant High Pressure Alarm
When the wall-mount unit receives a signal from the
compressor control module (CCM) indicating a high
pressure event, the wall-mount unit will generate an
alarm. Upon receiving the alarm, the wall-mount unit
will remove the "Y" call from the CCM, resetting the
status of the CCM. The alarm will stay present on the
wall-mount unit until manually cleared with TEC-EYE
hand-held diagnostic tool.
In addition to the CCM, the discharge pressure
transducer is used to prevent a high pressure event.
When the discharge pressure is above the discharge
pressure alarm setpoint (set 30 PSI below high
pressure switch, which is 650 PSI), the system will
disable stage 2 of mechanical cooling.
Phase Monitor
Used only on three phase equipment, the phase
monitor is a compressor protection device that will
prohibit operation of the compressor if the device senses
a possible reverse-rotation situation due to incorrect
phasing. On a call for compressor (and only compressor),
the device will check incoming phase, check for severe
voltage imbalance and check for proper frequency.
Under nominal conditions, a green LED light will show
on the face of the monitor. If there is improper phasing,
voltage imbalance or frequency deviation, the device will
show a red LED light and prohibit compressor operation.
If a fault condition occurs, reverse two of the supply
leads to the unit. Do not reverse any of the unit factory
wires as damage may occur.
Compressor Operation
The compressor will be enabled when the unit (in
orphan mode) or LV provide a cooling stage 1 call. The
compressor call from the controller has several delays
that may affect the start or stop time of the compressor
in regards to the cooling demand. The compressor has
a minimum on time of 120 seconds to prevent short
cycling the compressor. The compressor also has a
minimum off time of 120 seconds to prevent start
ups before the pressure in the refrigeration system
equalizes. When the second stage is engaged, it also
has a minimum run time of 120 seconds to allow the
system to stabilize before returning to single stage or
shutting down.
These delays can be changed by:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
TECHNICIAN password 1313.
3. Press UP or DOWN keys to scroll to Adv System
Config; press ENTER key.
4. Press UP or DOWN keys to scroll to Unit Config
B2; press ENTER key.
5. Press ENTER key to scroll to Min On or Min Off
(see Figure 40 on page 28).
6. Press UP or DOWN keys to change the value.
7. Press ENTER key to save value and move the
cursor to next parameter or top of screen.
8. Press ESCAPE key several times to return to Main
Menu screen.
Manual 2100-694B
Page
27 of 62
Advertisement
Table of Contents
Troubleshooting
