Power Source Considerations; Figure Appendix B-1 Transformer For Digital Equipment - Honeywell VPR100 User Manual

Appendix B
B.5 Power Source Considerations
Operate within limits
The AC power for the digital electronic equipment must be within the voltage and frequency limits
specified for that equipment. Attempts to operate outside the specified limits will result in no performance.
For those installations where the supply voltage will not stay within the specified limits, a ferroresonant
transformer, for voltage resolution, should be used.
Independent AC source
For protection against noise, the AC source for the digital electronic equipment should be independent of all
other loads especially when switching loads are involved. For example, it should not provide power for air-
conditioning, convenience outlets, lighting, motors, or similar noise- generating devices. To obtain e(see
Figure Appendix B-1) a separate transformer is required to supply power to the digital equipment. For
additional noise and transient rejection, shielded primary and secondary windings may be required. And, if
necessary, power line filters may be added to attenuate noise signals that have a higher frequency than the
power line frequency.
Transformer for digital equipment
Figure Appendix B-1 is an illustration of a separate transformer required to supply power to digital
equipment.
298
H
Power source
120/240 Vac
single phase
N

Figure Appendix B-1 Transformer for Digital Equipment

VPR & VRX – User Manual
H
To digital
electronic
equipment
N
G
20779
12/00