20
Johnson Controls, Inc. SLC Wiring Manual —
P/N 51870:G 04/23/2009
Wiring Requirements
Control Panel Terminal Blocks
Figure 2.3 Measuring DC Resistance of a Four-Wire SLC
2.3.2 Measuring Total Wire Length
The total wire length in a four-wire SLC cannot exceed the limits set forth in each system’s
instruction manual. The figure below identifies the output and return loops from SLC terminal on
the control panel:
Figure 2.4 Measuring the Wire Length of a Four-Wire SLC
2.4 Control Panel Terminal Blocks
2.4.1 IFC2-3030 and IFC-3030 with LCM-320, LEM-320
The IFC-3030/IFC2-3030 supports up to five pairs of loop control and expander modules,
providing from one to ten SLC loops. Loops can be either CLIP mode or FlashScan mode. SLC
loops connect to TB1 on the LCM-320 or LEM-320.
Figure 2.5 IFC2-3030, IFC-3030 SLC Loop Connections and Wiring
S
L
C-m
e
as5
.cdr
SLC Out
SLC Return
Short Point
SLC Return
SLC Out
STEP 2
STEP 3
First Device
Last Device
Last Device
First Device
B–
A+
B+
A–
SLC channel B
(output loop)
SLC channel A
(return loop)
SLC Terminal Block
SLC Loop Connections
on Loop Expander Module
SLC Loop Connections
on Loop Control Modules
LE
M3
20
-S
L
C
-TB
.c
d
r
