ABB SCC-U, Manual

Page: 18 / 32

18 SCC-U UTILITY UNIT | OI/SCC-U-EN REV. B
8 Maintenance / Repair
Safety instructions
CAUTION
Risk of injury
Risk of injury due to improperly performed maintenance work.
The operations described in this chapter require specialized
knowledge, and sometimes involve the necessity of working
on the utility unit with its cover open and live!
• Maintenance work must therefore only be carried out by
qualified and specially trained persons.
NOTICE
Damage to the device!
Damage to the device due to incorrect fuses.
• Only fuses of the specified type and rated current should
be used as replacements.
• Never use patched fuses.
• Do not short-circuit the fuse holder contacts.
When safe operation can no longer be assured
If it is apparent that safe operation is no longer possible, the
device should be taken out of operation and secured against
unauthorized use.
The possibility of safe operation is excluded:
• If the device is visibly damaged,
• If the device no longer operates,
• After prolonged storage under adverse conditions,
• After severe transport stresses.
Spare parts
Repair and maintenance activities may only be performed by
authorized customer service personnel.
When replacing or repairing individual components, use original
spare parts.
Cleaning
If necessary, clean the outside of the device with a damp cloth
and mild cleaning agents. Make sure that no water drops
penetrate into the device.
Checking gas path seal integrity
It is necessary to check the tightness of the gas paths regularly.
1. Block off all gas outlets.
2. Activate the power supply of the utility unit (otherwise, the
solenoid valves cannot be activated).
3. Apply a positive pressure of 100 mbar to the sample gas
inlet.
4. Using a U-pipe manometer (or other type) check the drop in
pressure; this must not exceed 1 mbar per minute.
5. Repeat steps 3. and 4. for all test gas inlets; the appropriate
solenoid valve must be activated.