RWB II ROTARY SCREW COMPRESSOR UNITS
PROPER INSTALLATION OF ELECTRONIC EQUIPMENT
S70-200 IOM
Page 48
3-PHASE
BUS
GROUND BUS
ELECTRONIC
CONTROL
ELECTRONIC
CONTROL
ELECTRONIC
CONTROL
PLANT SUPPLY
TRANSFORMER
ART4B
INCORRECT
Figure 43
3-PHASE
BUS
GROUND BUS
ELECTRONIC
CONTROL
ELECTRONIC
CONTROL
ELECTRONIC
CONTROL
PLANT SUPPLY
TRANSFORMER
ART4T
CORRECT
Never add relays, starters, timers, transformers, etc. in-
side an electronic control panel without first contacting
the manufacturer. Contact arcing and EMI emitted from
these devices can interfere with the electronics. Relays and
timers are routinely added to electronic control panels by the
manufacturer, but the manufacturer knows the acceptable
device types and proper placement in the panel that will keep
interference to a minimum. If you need to add these devices
contact the manufacturer for the proper device types and
placement.
Never run refrigerant tubing inside an electronic control
panel. If the refrigerant is ammonia, a leak will totally destroy
the electronics.
If the electronic control panel has a starter built into the
same panel, be sure to run the higher voltage wires where
indicated by the manufacturer. EMI from the wires can in-
terfere with the electronics if run too close to the circuitry.
Never daisy-chain or parallel-connect power or ground
wires to electronic control panels. Each electronic control
panel must have its own supply wires back to the power
source. Multiple electronic control panels on the same power
wires create current surges in the supply wires which can
cause controller malfunctions. Daisy-chaining ground wires
allows ground loop currents to flow between electronic con-
trol panels which also causes malfunctions. (Figure 43)
It is very important to read the installation instructions thor-
oughly before beginning the project. Make sure you have
drawings and instructions with your equipment. If not, call
the manufacturer and have them send you the proper in-
structions. Every manufacturer of electronic equipment should
have a knowledgeable staff, willing to answer your questions
or fax additional information. Following correct wiring proce-
dures will ensure proper installation of your electronic equip-
ment.
