Bell & Gossett 10 001 265R5 TechnoForce Pump Controller - Manual (Page 53)

TECHNOFORCE Installation, Operation, and Maintenance 47
Maintenance
6.8 Power Supply
The power supply provides 24 VDC for all digital and analog signals as well as the CPU. It is specifically rated
only for the controller and other loads should not be applied without factory approval.
The power supply is protected with both primary and secondary fusing as indicated on the wiring diagram. The
size of these fuses is indicated on a sticker inside each enclosure.
DANGER:
• Troubleshooting live control panels exposes personnel to hazardous voltages. Electrical troubleshooting
must only be done by a qualified electrician. FAILURE TO FOLLOW THESE INSTRUCTIONS COULD
RESULT IN SERIOUS PERSONAL INJURY, DEATH, AND/OR PROPERTY DAMAGE.
6.9 Protection
Analog inputs – the analog inputs provided on the TechnoForce Pump Controller must be wired according to
the wiring diagram that shipped with the unit.
Protection – all analog inputs are protected from high voltage, crossed wiring, etc. A sustained fault will be
limited to 20mA by the current limiting circuit.
Digital Inputs – as long as input power is derived from the integral 24VDC power supply they are protected.
Digital Outputs – each output shall not exceed the ratings on the digital output module.
6.10 Instruments and Their Use
With the diagnostics described herein extensive instruments are not required. However, the instruments used
should be quality units to meet the following at a minimum.
Under no circumstances shall any instrument be used to test any on board components. Especially risky is an
ohmmeter with battery voltage higher than TTL logic or applied with incorrect polarity.
6.10.0 AC/DC voltmeter
• Input impedance shall not be less than 10 MEGOHM.
• Accuracy - AC ± 2% of Full Scale
• DC ± 3% of Full Scale
• Rated circuit to ground voltage = 1000V.
6.10.1 Ohmmeter
• Accuracy ± 2%
• Overload protection voltage = 1000V.
6.10.2 Millimeter
• Accuracy ± 2% of Full Scale
6.10.3 Signal generator (analyzer) – recommended
A. Beta calibrator Model 434 20mA signal analyzer.
B. Altek calibrator Model 334 4-20mA loop analyzer.
Either instrument may be purchased from a Local Process Control Distributor.
NOTE: If some other instrument is used it must float above ground, preferably battery powered.