Principle of Operation
The Powerite BSD-1 Star-Delta Timer has been
designed to provide a Simple, Economical and Reliable Operation
for Star-Delta Motor Starters.
Powerite BSD-1 Star-Delta Timer
Features
Compact Size
Low Cost
Unique "Seal In" Contact
Simple Star-Delta Starter Wiring
Inbuilt Interlocks
Clear Operating Status
Delta Green LED
Star Red LED
Simple Adjustable Time Delay
Control Voltages up to 415V
BSD-1 Operating Details
When the Start pushbutton is operated the Line Contactor
and BSD-1 Timer are energised and both sealed in via
the instantaneous contact 8-3.
The Star Contactor is then energised via contact 8-5
and the Motor can now run up in Star. After the change over
set time has elapsed (adjustable up to 30 seconds) the Star
Contactor is de-energised via contact 8-5 and after a
50ms delay the Delta Contactor is energised via contact
8-6 and the Motor is now connected in Delta and remains
in this condition until the circuit is stopped.
Schematic Diagram for Basic Control Circuit
Schematic Diagram for Recommended Control Circuit
Technical Data
Rated Operating Control Voltage
Control Supply Voltage Tolerance
Rated Control Capacity (Resistive)
Fixed Transition Time (Star to Delta)
Operational Temperature Range
Adjustable Time Delay
Rated Mechanical Life
Rated Electrical Life
: 240V and 415V A/C. 50/60 Hz
: - 15% to + 10%
: 3A 250V A/C
: 1A 415V A/C
: 50 ms
: - 25 °C to + 80 °C
: 0.1 to 30 seconds
: 5 Million Operations
: 0.2 Million Operations
Function Diagram
Accessories
Standard Accessories:
The BSD-1 Star-Delta Timer is supplied with a (8) Eight
Pole Socket suitable for panel or DIN rail mounting and
a Retaining Bar Set to ensure the timer is securely fixed
into the socket at all times.
