Union Instruments CWD2005 SPC, Original Operating Instructions, Page: 97 / 110

Troubleshooting
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12.2 Changing/replacing fuses
Only skilled electricians or service technicians are permitted to replace fuses. Only
replace with fuse types specified by UNION.
12.3 Unstable measured value
•
The inlet pressure controller cannot maintain a constant inlet pressure. The
process pressure (blast furnace gas) is too high. A pressure booster pump
must be installed.
•
Direct solar radiation is causing rapid temperature changes.
Direct solar radiation must be prevented.
•
Air condition is causing the temperature to change too quickly. The cooling
capacity of the air conditioning is too high and the hysteresis is too large.
•
The inlet pressure is inexact/cannot be maintained.
Check whether the input pressure is too high.
12.4 Drift of measured value
The measured value drifts upward in one direction:
•
The calibration no longer achieves the required point. The frequency con-
troller is at its maximum value.
•
Heavy filter contamination that can no longer be corrected. The filter must
be replaced.
The measured value drifts downward:
•
The heat exchanger is contaminated with soot (when propane or butane is
combusted with too little air)
•
The heat exchanger must be cleaned (hot water) and then dried with com-
pressed air.
•
The thermal battery is contaminated.
•
The thermoelectric battery must be cleaned and carefully dried.
12.4.1 Incorrect ignition
The combustion calorimeter is continually igniting, the flame is burning. Combus-
tion calorimeter does not switch to the operation state.
•
Incorrect temperature setting (too high). The temperature threshold must
be reduced.
The combustion calorimeter switches to the operation state even though the flame
is not burning and then reverts to the ignition state.
•
Incorrect temperature setting (too low). The temperature threshold must be
increased.
Ignition electrodes are corroded, natural wear when ignition is frequent.
•
Replace the ignition electrodes.