Emergency Mode; Auxiliary Trip; Typical Control Methods - Danfoss VLT MCD 600 Operating Manual

VLT® Soft Starter MCD 600
Operating Guide
The soft starter trips on Lx-Tx Shorted on the first start attempt after control power is applied. PowerThrough does not operate if
control power is cycled between starts.
• PowerThrough is only available with in-line installations. If the soft starter is installed inside delta, PowerThrough will not oper-
ate.
• PowerThrough remains active until 3-Phase Control Only is reselected. While operating in PowerThrough, the trip LED flashes
and the display indicates 2 Phase - Damaged SCR.
PowerThrough uses a 2-phase soft start technology and extra care is required when sizing circuit breakers and protection. Con-
tact the local supplier for assistance.

9.5 Emergency Mode

Emergency mode allows the soft starter to run the motor and ignore trip conditions.
Emergency mode is controlled via a programmable input (input A DI-A, COM+ or input B DI-B, COM+). Parameter 7-1 Input A Func-
tion/parameter 7-5 Input B Function must be set to Emergency Mode. A closed circuit across DI-A, COM+ activates emergency mode.
When the soft starter receives a start command, it continues to run until a stop command is received, ignoring all trips and warn-
ings.
Emergency mode can be used with any command source.
Although emergency mode operation satisfies the functionality requirements of fire mode, Danfoss does not recommend its use
in situations that require testing and/or compliance with specific standards as it is not certified.
REDUCED EQUIPMENT LIFETIME
Continued use of emergency mode is not recommended. Emergency mode may compromise the soft starter and/or motor life as
all protections and trips are disabled. Using the soft starter in emergency mode voids the product warranty.
-
Do not run the soft starter in emergency mode continuously.

9.6 Auxiliary Trip

An external trip circuit (such as a low-pressure alarm switch for a pumping system) can be used to trip the soft starter and stop the
motor. The external circuit is connected to a programmable input (input A DI-A, COM+ or input B DI-B, COM+). To control the be-
havior of the trip, set the following parameters:
•
Parameter 7-1 Input A Function: Select Input Trip (N/O).
•
Parameter 7-2 Input A Trip: Set as required. For example, Run Only limits the input trip to when the soft starter is running only.
•
Parameter 7-3 Input A Trip Delay: Sets a delay between the input activating and the soft starter tripping.
•
Parameter 7-4 Input A Initial Delay: Sets a delay before the soft starter monitors the state of the input after the start signal. For
example, a delay may be required to allow time for pipeline pressure to build up.
• Parameter 7-10 Input A Name: Select a name, for example Input A Trip (optional).

9.7 Typical Control Methods

The requirements for an application differ between each installation, but the methods listed below are often a good starting point
for common applications.
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