Overload protection
This thermally activated device provides mechanical
overload protection for the motor(s) while in bypass
operation. It measures motor current and is set to the full
load amps (FLA) of the motor. A 1.2 x FLA service factor is
built-in and maintained, meaning that should the motor
current increase above that value, the overload will
calculate the level of increase to activate timing for the trip
function. The higher the current draw, the quicker the trip
response. It provides Class 20 motor protection.
1.4 Bypass Platform Configurations
The EMB is available in three platforms: EMB(0), EMB1, and
EMB2. The features available as options with each platform
are listed in
Table 1.2
. The ECB, also listed below, has all
option features available. See
5 Electromechanical Bypass
(EMB) Operation
for additional details on the EMB and
6 Electronically Controlled Bypass (ECB) Operation
for the
ECB.
Control Feature
EMB(0)
EMB1
EMB2
ECB
Safety Interlock
X
X
X
X
Common Start/
Stop
X
X
X
Automatic Bypass
X
X
Run Permissive in
Bypass
X
X
Basic Fire Mode
X
X
Advanced Fire
Mode
X
Serial Communi-
cation
X
Table 1.2 Bypass Configurations
Fused disconnect option
Disconnect and fuses
Circuit breaker option
Drive fuse option
or drive disconnect
and fuse option
mounted inside VDF.
24 V DC
internal use
SMPS
M1
Option
Line reactor
option
LC filter
option
M2
Dual motor option
OL1
OL2
Motor 1
Motor 2
M
M
M
M
M
Secondary
fuse
Control
transformer
120 V for
internal use
High Power
option
Primary
fuse
M3
Single motor option
Motor 1
Motor 1
Motor 2
Contactor motor select option
M2
M3
130BX207.10
Illustration 1.2 Bypass Circuit with Options
Introduction
Option Panel Operating Instructions
6
MG14I102 - VLT
®
is a registered Danfoss trademark
1
1
