Entelli-Switch 250 Controller 
Entelli-Switch 250 Controller 
Consists of two major assemblies: 
I.  The Micr
oprocessor contains the following: 
A.  Entelli-Switch 250 Board - Customer Input 
and Output (I/O) for system inter
face. Located 
on the left hand side of the back of the unit 
(see figure 6) 
1.  I/O accessories that can be found here are: 
a.  Engine start relay P output 
b.  Pre-Signal to transfer T3, W3 and 
UMD output (optional) 
c.  Transfer Inhibit Q3 and Q7 input 
(optional) 
d.  Remote test Q2 input (optional) 
e.  Network interface ZNET 
input/output (optional) 
B.  LCD and Keypad located on the exterior 
of the door (see figure 7) 
1.  User accessibility to the following: 
a.  LED indication of source 
availability 
b.  LED indication of transfer 
switch position 
c.  LCD screen indicates: 
(1)  timer count down (numeric) 
(2)  event reporting (text) 
d.  Keypad provides user interface to: 
[in conjunction with LCD screen] 
(1)  Setting sensors and timers 
(2)  Configuring logic accessories 
II.  The R/T bo
x (relay transformer box) contains 
the following: (see figure 6) 
A.  Relays which are required for controller output 
to energize the transferring mechanism of the 
transfer switch at line voltage. 
B.  Transformers which drop line voltage 
to control level for controller input. 
Engine Start Relay P 
I/O Interface 
Board 
Battery Strip 
and 
Access 
Code Label 
R/T Box 
Entelli-Switch 250 
Figure 6