Toshiba 18 - 1250 A Benutzerhandbuch

84 

Appendix 5 (cont.) External OL Relay Applications 

Across-the-Line (Direct-on-Line) Bypass  
A suggested control schematic is shown below for using the TE …-BP 
Series rated for Across-the-Line Bypass with an External Overload: 

In this example:  
The Start / Run command (2-wire or 3-wire) energizes a control Relay 
“CR”. If the selector Switch is in the “SS” (Soft Start) position, the 
contact of CR closes the 24VDC control signal to TB1, terminals 1 and 3 
of the TE Series, which begins ramping. When At-Speed status is 
reached, an internal Bypass Pilot Relay is used to close the Bypass 
Contactor. While in this mode, the TE Series CPU provides full motor 
protection, even when the Bypass Contactor closes.  
 
When the Selector Switch is placed in the “A-T-L” (Across-the-Line) 
position, a 2

nd

 isolated contact of CR is used to close the circuit between 

B1 and B2 of TB4 which are internally connected in parallel to the 
Bypass Pilot Relay contact in the Bypass Contactor coil circuit. Since 
the TE Series electronics may be out of service, an External Overload 
is added which only works in this mode and protects the motor by 
dropping out the connection between B1 and B2.