Contactors; Keypad Functions - Siemens SED2 VFD Operating Instructions Manual

SED2 VFD Electronic Bypass Option Operating Instructions

Contactors

The Controller board provides two or three relay contact circuits controlled by the Electronic
Bypass Option: bypass, input, and output contactors. Each circuit includes a NO relay. Controller
board connector J7 enables circuit connections. The relay circuits route power to the SED2 and
the motor via the contactors. Controlling the contactors through the relay circuits is the main
function of the Controller board.
Bypass Contactor – The bypass relay on the Controller board controls the bypass contactor.
The output and bypass relays are interconnected to 120 Vac Hot. This enables a safety circuit
that prevents the bypass and output contactors from simultaneously being energized.
Output Contactor – The output relay on the Controller board controls the output contactor.
Input Contactor – The input relay on the Controller board controls the optional input contactor.

Keypad Functions

Input
Contactor
VFD
Enable
Output
Contactor
STOP
Auto Bypass Enabled
RESET
Essential Services
INTERLOCK START LOGIC
2-CONTACTOR KEYPAD
Figure 4. Electronic Bypass Option Keypad Indicators and Pushbuttons.
The keypad provides user interface indicators and pushbuttons. The following table describes
specific pushbutton and indicator functions:
Pushbutton/Indicator
Input
On/Off
Enable
Hand
Start
Remote
Start
6
Bypass
Hand
Start
Bypass
Contactor
Remote
Overload
Start
Relay
Motor
VFD Fault
Safety Fault
Overload Fault
Enable Commanded Proofed
The Input On/Off pushbutton is supplied with the optional drive input
contactor. In VFD mode, this switch does nothing. In bypass mode, this
switch closes/opens the input contactor, switching the SED2 power on/off.
Enables SED2 operation by closing the input and output contactors.
Manually enables bypass mode operation by ensuring that the output
contactor is open and then closing the bypass contactor.
Activates the bypass mode and operates the bypass contactor according
to the status of the Remote Start input on the Controller board.
VFD
Input
Input
On/Off
Contactor
Bypass
Contactor
VFD
Enable Overload
Relay
Output
Contactor
Motor
VFD Fault
STOP
Auto Bypass Enabled
RESET
Safety Fault
Essential Services
Overload Fault
Enable Commanded Proofed
INTERLOCK START LOGIC
3-CONTACTOR KEYPAD
Description
Siemens Building Technologies
Bypass
Hand
Start
Remote
Start