Ametek TR-2100, Operation Manual

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TR-2100 User Manual 22
Digital Inputs
There can be between 16 and 160 digital inputs. These are normally used for monitoring the
operation of protection relays and switchgear via auxiliary contacts.
The digital inputs must have a DC power supply connected externally and the voltage must
be as specified in the System Drawings in Appendix V. When the contact being monitored is
closed, approximately 3 mA DC will flow through the contact.
On the analogue cards each group of 4 inputs is isolated from each other group and has a
common connection (marked C) for the field control voltage (FCV). This common
connection may be wired to either the battery positive or negative terminal. On the digital-
only cards there are 16 inputs arranged in isolated groups of 4, and there are 16 inputs
individually isolated. The normal state of the input is defined in the recorder configuration in
Display Station. The signal is displayed as being in the “Normal” or “Alarm” state.
Status Output Connections
The four status relay output circuits are available on the 16-terminal orange connector at the
right of the rear panel. The relays outputs are normally open, dry contacts in the shelf
(unpowered) state. The functions of these relays are described in the previous chapter.