CSR-20 & CSR-40, September 1999
NOTE: The following procedures involve servicing
the refrigeration system. Some of these service pro-
cedures are regulated by Federal, and in some
cases, by State and Local laws.
All regulated refrigeration service procedures
must be performed by an EPA certified technician,
using approved equipment and complying with all
Federal, State and Local laws.
NOTE: Hermetic units feature a large, one-piece filter
drier/in-line filter. The filter drier should not require
replacement unless major system contamination
requires evacuation and cleanup of the refrigeration
system.
Hermetic Refrigeration System Diagnosis
Procedures
A hermetic refrigeration system is a totally sealed system that
is highly reliable, and virtually leak and tamper proof.
Consequently, CSR hermetic refrigeration units do not have
service valves, schrader fittings or sight glasses to aid diagno-
sis and service procedures. Instead, system performance is
easily and quickly verified by initiating an automatic Full
Pretrip Test using the
µ
P-D controller keypad.
A Full Pretrip Test should be performed during pretrip
and routine maintenance inspections. If the unit fails the Full
Pretrip Test, view and write down each alarm code. Then
identify, diagnose and correct all potential mechanical and
electrical system problems first. If a mechanical or electrical
system problem was detected and corrected, perform another
Pretrip Test to verify unit performance and operation. If the
unit still fails to cool properly, identify and diagnose all poten-
tial refrigeration system problems before opening the refrigera-
tion system.
System Diagnosis Using the Full Pretrip Test
To verify system performance or diagnosis a unit cooling or
heating problem, perform a Full Pretrip Test.
1.
Turn the unit On/Off switch ON.
2.
Press the PRETRIP key. The display will flash “ENTER
PTRIP”.
3.
Press the ENTER key. The display briefly shows “LOAD
PTRIP”. The controller then conducts a Full Pretrip Test.
NOTE: The controller will not perform an auto-
matic pretrip test until all existing alarms have
been corrected and cleared.
•
If a Check Alarm fault occurs during a pretrip test,
the Alarm LED turns ON while the controller contin-
ues the Pretrip test.
•
If a Shutdown Alarm fault occurs during a Pretest
test, the Alarm LED FLASHES and the controller
stops all unit operation.
4.
When the Pretrip test is complete, the display returns to
the Standard Display (e.g. setpoint and controlling sensor
temperatures). The unit returns to normal operation.
5.
If the Alarm LED is ON or flashing ON and OFF, press
the ALARM key to view the alarm code(s).
• The left display shows the number of alarms stored in
memory (e.g. ALM 2).
• The right display shows a two digit code for the most
recent alarm (e.g. 50). A hyphen (-) will appear in the
controller display in front of all alarms codes that occur
during a pretrip test (e.g. -50).
6.
Write down the alarm code in the display. Then press the
DOWN key to view the next alarm code.
7.
Repeat step 6 until all alarm codes have been recorded.
6
Refrigeration System
Diagnosis and Service
