Despatch LCC1-87NV-2 - Manual (Page 33)

24
Tests
Tests should be performed carefully and regularly. The safety of personnel as well as
the condition of equipment may depend upon the proper operation of any one of these
controls at any time.
Nitrogen Supply Check
This test is necessary in nitrogen models only.
1.
Turn the inert atmosphere valve on
the control panel to the OFF
position.
2.
Screw the adjusting knob on the
flowmeters clockwise all the way to
the OFF position. The adjusting
knobs must be off on both the
PURGE and MAINTAIN flowmeters.
3.
Open the tank valve on the nitrogen supply and set the pressure regulator to
about 40 psi.
4.
Check the nitrogen plumbing for leaks using a soapy water solution. As nitrogen
gas is odorless, all leaks should be stopped to prevent the possibility of
suffocation in a small work area in which a nitrogen leak might displace much of
the oxygen in the atmosphere.
Control Output Check
1.
On a cool oven (< 100 C or 212 F), adjust CONTROL setpoint to 20 F (11 C)
higher than current actual chamber temperature.
2.
Set HEATER switch to ON.
3.
When the CONTROL output indicator light is on, the HEATER indicator should
also be on.
4.
When the CONTROL output indicator light turns off, the HEATER indicator light
should also turn off. If the HEATER light remains on, the SSR may be shorted.
You can also verify the CONTROL output by measuring across the output (+ and
-) terminals with a voltage meter. The output should measure >4 VDC when on,
WARNING: High voltage is present on terminals,
voltage checks should be made only by
qualified electrical maintenance personnel:
e.g. electrician or technician. Failure to
heed this warning can result in serious
bodily injury, property damage, or death.