Mains connection, minimum time for switching cycles, charging current limitation

Question:
The Operating Instructions of 9300, 8200, 8200 motec (E82MV) and 8200 vector (E82EV) and ECS controllers demand a period of 3 minutes before reconnection.
What are the frame sizes' differences within the device series?

Answer:
The 9300, 8200, 8200 motec and 8200 vector drive controllers with DC bus have a switch-on charging current limitation.

3 minutes after switching off
Smaller frame sizes of 9300 and 8200 drive controllers are fitted with NTC resistors:

• 9321, 9322
• 8241, 8242
• 8200 vector 0.25 - 0.37 kW

The Operating Instructions demand a period of at least 3 minutes between disconnection and reconnection.
If they are cold, the NTC resistors are of high resistance; thus, they can limit the charging current. During the first charging of the DC bus the temperature rise causes a drop in resistance, until they have more or less no resistance at all for the normal recharge operation. This shows that after switching off there must be a cooling phase before the current limitation can operate as intended again.

3 minutes after the last switching on
Bigger frame sizes of 9300, 8200, 8200vector 0.55 - 90 kW and 8200motec drive controllers are fitted with limiting resistors and bypass relay:

• ≥ 9323
• ≥ 8243
• 8200 vector from 0.55 kW on
• 8200 motec 3.0 - 7.5 kW
• (ECS axis module, when C0175 = 1 or C0175 = 2)

A reconnection of these devices is already possible after a period of 3 minutes after the last switch on (time between two switch-on processes).
The limiting resistor is bypassed by a relay contact directly after charging, so that it can cool immediately. Here, cooling is effected simultaneously to the normal operation. After 3 minutes of cooling phase the mains can be switched on again independently of the switch-off time without resulting in overheating. For safety reasons the drive controller should not be reconnected before the DC-bus voltage has decreased to such a degree that the bypass relays of the charging resistors open (LU-message is displayed).

For following devices the mains switch on cycle time is not restricted:

• 8200motec 0.25 - 2.2 kW
• ECS supply module
• ECS axis module (setting C0175 = 3)

Note:
The ECS axis modules have a charging current limitation including a limiting resistor and bypass relay, which can be deactivated via C0175 = 3 (resistances continuously bypassed). According to Lenze factory default setting this charging current limitation is active, so that a period of 3 minutes between two switch-on processes is to be considered.
The ECS supply module contains a controlled thyrister charging switch for limiting the charging current after switch on, so that a cooling phase is not required.

URL for linking this AKB article: https://www.lenze.com/en-de/go/akb/20023430/1/