Specifications

33
INSTALLATION & SETUP • CONNECTING A COMMAND RELAY UNIT
TECHNICAL SUPPORT 978-486-0086 • [e-mail] • www.burk.com
Floating Grounds
You may use an isolation amplifier if the metering or status inputs
have a floating ground. If any ground for these inputs is a floating
ground, it must be connected to an isolation amplifier before you
connect it to the Wiring Interface. The VRC2500’s inputs will not
tolerate a floating ground.
The Command Relay unit provides isolation between your GSC
or VRC unit and your equipment. Each Command Relay unit can
connect up to eight Command output channels.You will need two
Command Relay units to make all the channel connections on a
16 channel unit. No soldering is required.
Connecting a
Command Relay Unit
CONNECTING INPUTS
1. Wire your equipment to the provided three-terminal push-on
connectors. Insert the correct wire into the connector opening
and tighten down the top screw. One three-terminal push-on
block is provided for each relay. Each Command channel has
two relays: A and B. The three terminals in the push-on
connector correspond with the contacts on the back panel of
the Command Relay unit (standard Form C, from left to right):
NO (normally open), NC (normally closed), and C (common).
Insert the push-on connector into the back-panel connector
on the Command Relay unit, with the set screws facing up.
WARNING! Carefully
position your push-on
Connectors in relation to
the screened legend on the back of
the unit. Overlapping from one
channel to the other can cause
improper command-channel
operation or damage to your
equipment.
The Command outputs on
the I/O unit are open
collector outputs,
maximum 250 mA 30VDC,
momentary or latching. The
Command Relay Unit is required if
the current draw is more than 250
mA or to provide protection and
isolation for your GSC or VRC unit.
✍✍
!
Power is supplied through
the DB37 command-output
connector. No external
power is required for operation
with a GSC3000 or VRC2500
system. If used with the VRC2000,
the Command Relay Unit will
require an optional power supply
for proper operation.
✍✍