Using the line contactor

Proceed as follows:

  1. Always place the line contactor before the line filter and line choke (if present).
  2. Use at least one contactor of utilization category AC‑3 (EN 60947-4-1) as a line contactor.
  3. NOTICE! Failing to observe the minimum switch-off time of the line contactor can cause material damage. Irreparable damage to the inverter or unforeseen malfunctions. After switching off the voltage supply, keep it switched off for at least 10 s.
    • Do not switch the voltage supply on or off more often than once per minute.
  4. Do not use the line contactor for jog mode, but only for switching on and off.

The following table provides an overview of when a line contactor is required. Observe the notes on the required protective measures for the braking resistor used in the product manual > chapter Protecting the braking resistors from thermal overload.

Inverter

Braking resistor

Protective element/
preventive measure

Line contactor
required?

Sizes 1 – 3

No BW..

–

No

BW.. Flat design

–

No

BW.. as PTC

–

No

BW..

External overload relay

Yes

BW..-T

External overload relay

Yes

From size 4

No BW..

–

No

BW.. Flat design

–

No

BW.. as PTC

–

No

BW..

External overload relay

No

BW..-T

Temperature contact
evaluation

No

If a braking resistor is connected to the inverter from size 4 without using a line contactor, an external DC 24 V voltage supply must be provided on the inverter.