Ground Fault Protection; Overview; Connect The Ct To The Ground Fault Inputs; Configure Ground Fault Protection Settings - Danfoss VLT Soft Starter MCD 600 Installation Manual

Modbus RTU Card
Installation Guide

6 Ground Fault Protection

6.1 Overview

Ground fault protection is only available on ground fault enabled option cards with soft starters running a compatible version of
software. Contact the supplier for assistance.
The Modbus RTU Card can detect ground current and trip before the equipment is damaged.
Ground fault protection requires a 1000:1 or 2000:1 current transformer (not supplied). The CT should be rated 1 VA or 5 VA. The soft
starter can be configured to trip at 1–50 A. If ground fault current rises above 50 A, the soft starter trips immediately.
Parameter 40-3 Ground Fault Trip Active selects when ground fault protection is active.

6.2 Connect the CT to the Ground Fault Inputs

To use ground fault protection, a common-mode current transformer (CT) must be installed around all 3 phases.
Procedure
1. Use a 1000:1 or 2000:1 CT with a rating of 1 VA or 5 VA.
2. Set parameter 40-5 Ground Fault CT ratio to match the CT.
3. Connect the CT to the ground fault terminals (G1, G2, G3).
For maximum protection, the CT should be installed on the input side of the soft starter.

6.3 Configure Ground Fault Protection Settings

Ground fault protection settings must be set in the soft starter.
Parameter
Parameter 40-1 Ground Fault Level
Parameter 40-2 Ground Fault Delay
Parameter 40-3 Ground Fault Trip Active
Parameter 40-4 Ground Fault Action
Parameter 40-5 Ground Fault CT Ratio
16 | Danfoss A/S © 2022.11
N O T I C E
Description
Sets the trip point for ground fault protection.
Shows the response of the Modbus RTU Card to ground fault variation, avoiding trips
due to momentary fluctuations.
Selects when a ground fault trip can occur.
Selects the response of the soft starter to the protection event.
Set to match the ratio of the ground current measuring CT.
Ground Fault Protection
AQ277154312778en-000201 / 175R1180