Edwards (GFD) Ground fault detection module

The Edwards GFD ground fault detector monitors power-limited isolated circuits for ground faults. First, the module checks two circuit pairs continuously every 16 seconds. As a result, it detects a ground fault within 20 seconds on circuits up to 10 kilo-ohm. The Edwards GFD then signals the condition via built-in relay contacts or via ground-fault transfer to the host panel.

This is a stand-alone unit designed primarily for FireWorks applications. Specifically, the GFD detects ground faults on the RS-232 communication line between a FireWorks workstation and a control panel. Therefore, deploy it on each RS-232 link in mission-critical FireWorks installations.

Verified Electrical Specifications

The Edwards GFD operates on 10 to 28 VDC supplied from a UL/ULC listed 24 VDC fire alarm panel. Then current draw is 110 mA. The trouble contact carries 1 A at 30 VDC resistive load. Also, polarity is not important on the power input.

Configuration via JP1

Jumper JP1 sets the device behavior. Specifically, with JP1 in position 1-2, the GFD connects the COM output to earth ground through a 1 kilo-ohm resistor – letting a ground fault transfer to the host panel. In contrast, JP1 in position 2-3 routes ground-fault status through the dry relay contacts for connection to a monitor module or zone card.

LED Indicators

The GFD has two yellow LEDs identifying which conductor pair has a ground fault. For example, LED 1 lights for a fault on conductor 1. Then LED 2 lights for a fault on conductor 3. Also, the module has a watchdog circuit that keeps the relay energized to verify continuous operation.

Mounting

The Edwards GFD mounts inside a panel cabinet on a SIGA-MP2L mounting plate, in an electrical box next to the panel, or in an MFCA cabinet next to the panel. Compatible boxes: 2-1/2 inch deep 2-gang or 4-inch square 1-1/2 inch deep with 2-gang cover. Furthermore, the construction is high-impact engineering polymer for durability in panel-cabinet installations.

For more information, contact the Life Safety Consultants team at (888) 557-0558, or email us at: sales@lifesafetycom.com