Hach 1950Plus, Инструкция по эксплуатации инструмента, Страница: 34 / 188

Page 34
Wiring the Instrument
UVTOCUnpacking Installation Setup.fm
Section 2
For process or industrial applications, the national electrical codes of most
countries require that ac service feeds be hard-wired and contained in
conduit systems. This analyzer has been designed to conform to this
requirement.
The manufacturer recommends conduit for two reasons:
1. It is generally required by most local electrical codes, and
2. Use of metal conduit can improve immunity to lightning surges and
ac power transients.
Additionally, electrical and instrumentation standards require a local means of
removing power from the instrument.
In hard-wired electrical applications, the power and safety ground service
drops for the instrument should be no longer than 6 meters (20 feet) unless
metal conduit is used to shield the ac power wiring.
The analyzer is internally fused on
only the hot (
1) phase.
If 2-phase power is used,
(HOT
1, HOT 2) the customer
must provide external circuit
overcurrent protection on the
HOT (
2) line to the analyzer.
All wiring connections are made through the customer connection gland plate
in the upper left side of the instrument enclosure. Choose the knockouts
carefully and remove only those that are needed. Wire the instrument for
power, alarms, and relay connections using the supplied sealing-type conduit
fittings to maintain the environmental rating. See
Figure 12 on page 35 . If a
conduit opening is unused, install an oil-tight seal in place of the plugs to
maintain the environmental rating.
Connections to ac power are made at the connection terminals shown in
Figure 15 on page 37 and are accessible when the Customer Access (power
supply) cover is removed. See Figure 13 on page 36 .
Important Note: The analyzer circuit board components are sensitive to static
electricity damage. Do not touch circuit boards or their components without wearing a
properly grounded wrist strap. See
Electrostatic Discharge (ESD) Considerations on
page 111 .
Use 2-con PE wire that is the correct size for the connector
openings and is rated for the maximum equipment current.
See
Technical Specifications on page 13 . Install an isolating switch or circuit
breaker within easy reach of the instrument. Clearly mark it as the
disconnecting device for the equipment. Fit the supply with an overcurrent
protection device (breaker switch) rated at 20 amps maximum.