Electrical Connections
The MR1 Mini-Remote requires a two-wire connection (field-
supplied) to communicate with the Environmental unit under its
control. The stranded twisted-pair connects to the MR1 interface
board at TB2-11 (T+) and TB2-12 (T-). Refer to Table 1 below
for the connections at the Environmental unit. Note that
maximum length for RS-422 communications is 1000 feet, and
minimum of 22 gauge wire should be used for all field wiring.
Power for the MR1 is supplied to TB3-1 and TB3-2. Maximum
current draw is 0.3A at 24VAC. It is recommended that the
MR1 be powered independently from an external 24VAC
transformer; optionally, it may draw power from the
Environmental unit. However, if the MR1 is located greater
than 300 feet (100 meters) from the Environmental unit, an
external transformer must be used.
Caution: Ensure Environmental
unit has sufficient 24VAC power
to support the MR1, Liqui-tects
or any other auxiliary device.
Liebert
Environmental
Controller
24VAC
Auxiliary
Power
Connection to MR1
TB2-11 (T+)
TB2-12 (T-)
SM - Standard
AM/AG - Advanced
L10 - Level 10
Microprocessors
Terminal T5
Terminal G5
Terminal 78 (T+)
Terminal 77 (T-)
L00 - Level 00
Microprocessor
TB1-1
TB1-5
Terminal 78 (T+)
Terminal 77 (T-)
Mini-Mate 2 - TB4-1 (T+)
TB4-2 (T-)
SSC - Small System
Controller
- TB2-1 (T+)
TB2-2 (T-)
Table 1: Connection Summary
The MR1 provides a Common Alarm Output, at TB2-9 and
TB2-10. This dry-contact is rated for 5A, at 24VDC or
120VAC.
There are four optional Customer Alarm inputs that may be used
on the MR1 (see Hardware Configuration). The inputs are
triggered by contact-closures, and the contacts are rated for 5A,
at 24VDC or 120VAC as well. The connection points and
display mapping are as follows:
NOTE: New Feature. The inputs
are now contact-closure –
24VAC powered inputs are no
longer necessary.
Local Alarm 1: TB2-3 & TB2-4
NOTE: Exercise caution if
installing new MR1 as
replacement unit: remove power
from signal inputs, or damage to
unit may occur!
Local Alarm 2: TB2-1 & TB2-2
High Water Alarm: TB2-5 & TB2-6
High Head Alarm: TB2-7 & TB2-8
Liebert MR1 •5
