Mitsubishi FR - S500 instruction manual Design Information, MC1

1.10 Design Information

1)Provide electrical and mechanical interlocks for MC1 and MC2 which are used for commercial power supply-inverter switch-over.

When there is a commercial power supply-inverter switch-over circuit as shown below, the inverter will be damaged by leakage current from the power supply due to arcs generated at the time of switch-over or chattering caused by a sequence error.

2)If the machine must not be restarted when power is restored after a power failure, provide a magnetic contactor in the inverter's primary circuit and also make up a sequence which will not switch on the start signal.

If the start signal (start switch) remains on after a power failure, the inverter will automatically restart as soon as the power is restored.

3)Since the input signals to the control circuit are on a low level, use two or more parallel micro signal contacts or a twin contact for contact inputs to prevent a contact fault.

4)Do not apply a large voltage to the contact input terminals (e.g. STF) of the control circuit.

5)Always apply a voltage to the alarm output terminals (A, B, C) via a relay coil, lamp etc.

6)Make sure that the specifications and rating match the system requirements.

1) Commercial power supply-inverter				3) Low-level signal contacts
switch-over
			MC1
			Interlock
Power	R<L1> U		IM
supply	S<N>	V
			MC2
	T	W	Leakage current	Low-level signal contacts	Twin contact
	Inverter

44