West Control Solutions N8080 (for 2xxx) - Manual (Page 22)

1.3.1 Mains (Line) Supply
The Indicator will operate on 90 - 264V AC 50/60Hz mains (line) supply. The power
consumption is approximately 4 watts.
CAUTION: This equipment is designed for installation in an enclosure
which provides adequate protection against electric shock. Local
regulations regarding electrical installation should be rigidly
observed. Consideration should be given to prevention of access to
the power terminations by unauthorised personnel. Power should be
connected via a two-pole isolating switch (preferably situated near
to the equipment) and a 1A fuse, as shown in Figure 1-4.
If the Indicator has relay outputs in which the contacts are to carry mains (line)
voltage, it is recommended that the relay contact mains (line) supply should be
switched and fused in a similar manner but should be separate from the Indicator
mains (line) supply.
1.3.2 20 - 50V AC/DC Supply
Power should be connected via a two-pole isolating switch and a 315mA
slow-blow (anti-surge Type T) fuse. With this option fitted, the Indicator will accept
20 - 50V AC @ 50/60Hz or 20 -50V DC in the polarity shown in Figure 1-4.
1.3.3 Process Input
The process input will accept millivolt, volt and milliamp DC ranges.
1.3.4 Digital Input Option
Terminals 16 and 17, when this option is fitted, may be used for either of two
functions (selectable in Configuration Mode); (a) Tare facility or (b) Security facility.
These terminals may be connected to (a) the voltage-free contacts of a switch or
relay, or (b) a TTL-compatible voltage. With the required function selected in
Configuration Mode (see Subsection 3.4), operation is as follows:
1-4 Volume II PM091-1
59136
Voltage Free Operation
TTL-conpatible
Operation
Tare Facility Security Facility
Contacts open Signal >2.0V Current process
variable value used
as new “zero” point
to create an
automatic offset.
Entry into Program
Mode prohibited
Contacts Closed Signal <0.6V No automatic offset
applied.
Entry into Program
Mode permitted