Relay ratings
RL1 and RL2 are normal control relays, which are used to energise relay RL3. PCB-mounted OEN Type 57 relays rated for 12 volts (or equivalent) may be used for the purpose. RL3 and RL4 are required to support the complete line current during star as well as delta configurations. Hence the contacts must be rated to withstand full line-to-line voltage and expected full current of the motor in delta configuration. Thus heavy-duty power relays of appropriate voltage and current rating for 12V coils must be used. The relays are to be mounted outside the PCB on the chassis of a suitable metal cabinet, which must be earthed properly to avoid any risk of shock.
Before connecting the motor to the circuit, proper operation of the relays must be checked. The windings must be connected as shown in the circuit diagram.
Construction
A single-side PCB for the automatic 3 phase induction motor starter circuit is shown in Fig. 2 and its component layout in Fig. 3.
Thanks
Status of 7th pin of 555
Kindly elaborate your query.
is there any connection at pin 7 of 555 timer?
what components are connected in place of Y1, Y2, B1, B2, R1, R2…?
sorry, i forgot that ryb are the windings of three phase induction motor.
How to protect this circuit for the motor and what are the advantages for this circuit?
What is the benifit of this circuit ?
Which is the benifit for this circuit?
Can you share Gerber file and schematic to upgrade and simulate it in Circuit designing software and Simulate.