Automatic shutdown

CCST current-controlled shut-off system without delay

We have developed a new control board CCST (Current Control Switch Timer), which detects the shut-off and ensures that the main contactor safely disconnects despite the generator effect of the motor. This control board ensures that in the case of a brief power interruption (greater than 0.2s), no restart occurs and when the power coupling is disconnected, the pins of the SSK or the power line are voltage-free within a maximum of 0.6s. Thus, we safely meet the requirement according to DIN EN 60204 with a maximum of 60V after 1s.

The current-controlled shut-off system opens a relay in self-holding mode during a power supply interruption. If the power supply is resumed afterwards, uncontrolled restarting of a machine is safely prevented. Unlike a voltage monitoring relay, this works even when a rotating machine with inertia still induces a voltage.

The shut-off system receives its operating voltage via terminals L1 and N.

The control signal of the after-run control is the load current of the connected consumer. The controlling consumer is connected between terminals L1 Load and N.

When the consumer is switched on, the relay pulls in without delay and connects contact SP with terminal N. As soon as the load current is interrupted, the relay is opened again without delay. The relay thus controls the self-holding circuit.

Depending on the version, the module may only be operated at 230V or 400V.

There must be a protection device for this module.

When applying the operating voltage to the shut-off system, the relay closes briefly. This implies that an electromechanical contact of the contactor must be in series with the SP contact. The operating voltage must also be present at the shut-off system before the consumer is switched on.

If a potential-free switching contact is required, the bridge (through-hole) between terminals N and NSP must be separated using a 3mm drill. The copper ring around the hole should be completely removed. The switching contact of the relay is then between SP and NSP.