Cocoon CWS 4000 - Temperature Limit Thermostat Test Procedure

Care Essentials CWS4000 Cocoon Warming System Service Manual
4.4. Temperature Limit Thermostat Test Procedure
The CWS4000 temperature limit thermostat test is completely optional and may be performed at
the discretion of those responsible for the technical management of the CWS4000. The
CWS4000 temperature limit thermostat function does not require adjustment, calibration or
performance inspection.
The maximum delivered air temperature is not only limited by the control system but by two
series-connected bimetallic auto-resetting thermostats. These thermostats are located in the
exhaust air stream and will interrupt power to the CWS4000 should the output air temperature
exceed a predetermined limit. Either of these two independently operating thermostats will
remove power from the CWS4000 if the delivered air exceeds a preset high limit temperature,
automatically restoring power when the thermostat temperature fails to a safe level.
This test procedure may be briefly described as follows. The CWS4000 is set up with the
various items required to perform the test. The CWS4000 is energised and operated at a set
temperature of 46°C until it has “warmed up.” The test is commenced through a special process
that switches the heater on continuously, simulating a possible fault condition. The test time and
delivery hose air temperature are monitored. The test is passed if the CWS4000 is de-energised
less than 8 minutes after the test start. The delivery hose air temperature at the conclusion of
the test may be as high as 60°C. Note that this test will only produce a valid result if it is
performed at an ambient temperature of 21°C, or greater.
Items Required:
e CWS4000 Operator and Service Manuals.
e Personal Computer (PC) with a free serial communications (Com) port and a suitable
Terminal program, eg HyperTerminal™, which is provided with Microsoft Windows™,
e Digital Thermometer.
e CWS4000 RS232-Logic Communications Cable
The Cocoon Warming Machine model CSW4000 can have three different versions for the
test cable.
This cable is for the over temperature performance testing.
Details of the three versions are:
A. Machines with Serial Numbers commencing 4-0001 Yellow Dot
B. Machines with Serial Numbers commencing 4-0100 Red Dot
C. Machines with Serial Numbers commencing 4-0200 Green Dot
In the event you need to access any of these cables please contact your location Distributor or
Care Essentials Pty Ltd.
Revision | 13 June 2006 Pade 10