Power Source Considerations; Figure 9-1 Transformer For Digital Equipment - Honeywell UDC3300 Product Manual

9.5

Power Source Considerations

Operate within limits
Independent AC
source
Transformer for digital
equipment
100
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.
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 electrical isolation (see Figure 9-1) 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.
Figure 9-1 is an illustration of a separate transformer required to supply
power to digital equipment.
Figure 9-1 Transformer for Digital Equipment
Power source
120/240 Vac
single phase
UDC3300 Limit Controller Product Manual
H
H
N N
G
To digital
electronic
equipment
20779
1/01