HP 11744195 - Manual (Page 19)

Chart Environmental Chambers System Maintenance
System Maintenance
Maintenance of this equipment should be done by a qualified technician. High voltage
electrical systems, cryogenic plumbing, and mechanical systems all represent a potential
for injury or death. The main power must be removed from the chamber, and the liquid
nitrogen supply should be disconnected prior to servicing this equipment. It is a good
practice to keep a maintenance log for the system. The log should contain the tasks that
must be accomplished and when they were performed.
Chart Industries does offer a service contract in which we will send a technician out to do
routine maintenance items. Different plans are available. If interested, please call 1-888-
877-3093 for details.
❏
Maintenance Tasks to be Performed on a Daily Basis:
1. Check the high and low temperature settings of the air safety controller to insure that
they are set to the appropriate settings for the product that is being tested. The high
temperature set point (SP) should never be any higher than 200
° C. The low
temperature set point (AL-2) should never be set lower than -80 ° C.
2. Make sure that the LN
2
supply is on and that there is sufficient LN
2
to perform your
test. The pressure of the LN
2
should also be verified and maintained at less than 175
psig.
❏
Maintenance Tasks to be Performed on a Monthly Basis:
1. The proper function of the safety control devices should be checked on a regular
basis. Replace any items that may be damaged or worn. These would include the
ON/OFF switch and door proximity switch.
2. Check the air safety circuit high temperature trip point by lowering the setting of the
product safety (SP) below 30 ° C and programming the system set point to 45°C to
verify that the safety circuit trips at the high temperature it was set for and heating is
disabled. Check the product safety circuit low temperature trip point (AL-2) by
raising the setting of the air safety (AL-2) above 0
° C and programming the system set
point to -15°C to verify that the product safety trips at the low temperature it was set
for.
3. The electrical compartment should be kept clean and vacuumed if necessary.
4. The current draws of the major components (blower motor and heater) should be
checked with an amp probe and recorded for future reference to determine if there is
any irregularity. Extreme caution must be taken whenever working with high voltage
components. Increased current draws may be an early sign of heater problems.
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