Procedure 20 - Alarm And Sensor Test - Invacare 6LXO2 Service Manual

ALARM TEST

PROCEDURE 20 - ALARM AND SENSOR TEST

TO PREVENT ELECTRICAL SHOCK, ALWAYS DISCONNECT CONCENTRATOR FROM
ELECTRICAL OUTLET BEFORE SERVICING.
CHECK ALARMS PERIODICALLY FOR PROPER FUNCTION.
To check each alarm, perform the following:
1. POWER LOSS - With the unit running, remove the line cord from power source. The power loss alarm
mode should sound the audible alarm immediately or within 30 seconds.
NOTE: With the unit unplugged and inoperable for a short period of time, the Battery Free
will be drained. If power failure alarm does not sound with unit unplugged and power switch on,
TM
the Battery Free circuit is drained. It will recharge when unit is plugged in and switched on.
2. LOW PRESSURE TEST- There are two (2) seperate failure modes for Low Pressure.
a. Low product tank pressure (pressure in tank drops below a preset value, typically 7 p.s.i).
b. Failure to reach the set point pressure within a prescribed time limit, or Timeout Failure.
Test each in the following manner:
Low Pressure Test (FIGURE 1).
c1. With unit running, set flow at maximum rating. When the main valve switches, pull the stem on the
compressor relief valve out as far as it will go and hold it. The low pressure alarm should activate within 30
seconds. (Refer to FIGURE 5 for Shutdown Mode.)
c2. With unit running, set flow at maximum rating. Remove the P.C. board tubing (tywrap) from the top
of the product tank The low pressure alarm should activate within 30 seconds. (Refer to FIGURE 5 for
Shutdown Mode.) Replace tubing and tywrap.
Time-Out Test (FIGURE 1)
d. With unit OFF, disconnect the compressor connector from the main wiring harness. Plug
unit in and turn power ON. The Time-Out Failure alarm should activate within 40 seconds. (Refer
to FIGURE 5 for Shutdown Mode.)
NOTE: If any alarm fails to perform to specification, contact Invacare Technical Service.
Compressor
CAUTION
CAUTION
Relief Valve Stem
[Pull Out to Simulate
Leak (STEP 2-a)].
Compressor
FIGURE 1 - LOW PRESSURE TEST
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PROCEDURE 20
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Compressor Molex Connector
[Disconnect from
Harness(STEP 2-b)].
A
L
A
R
M
T
E
S
T
circuit