Installation guide

23
1101 C-LEM
MODEL 1101 COMMAND LEM (C-LEM)
L The Model 1101 Command Line Encoder Module (C-LEM) is a remote switching module that
may be installed anywhere along the LEM line. The revised C-LEM MK II is fitted with an
SPDT relay which is capable of switching a 2-amp, resistive load at 24 volts DC. The original
C-LEM MK I (now discontinued) is described later on page 24. Similar to D-LEMs, C-LEMs
have to be programmed to certain address values that determine their function and how they will
operate. (See the OUTPUT ASSIGNMENT table for details, pages 28 and 26). Unlike D-LEMs,
several C-LEMs may be programmed to the same address, in which case they will all respond
identically. C-LEM addresses are not monitored by the panel and therefore the panel does not
know if any C-LEMs are connected. C-LEMs are coded similarly to D-LEMs, with address
values 1 to 54 being valid.
The decoding electronics on the C-LEM printed circuit board are powered from the LEM line;
however, the on-card relay coil requires an external source of power. It is imperative that this
power be supplied from the APLEX control panel's auxiliary power terminals 28 (-ve) and 32 or
33 (+ve). Connection can be made by using a second quad for power. The use of an extra
field-installed power supply, powered from a different phase or branch circuit than the main
panel, has created severe problems in the main panel.