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Other Ground Monitors

GMS-504DZ GM / GFR Combo

The GMS-504DZ with 4DZ TechnologyTM is a state-of-the-art ground monitoring system that combines a patent-pending, digital Ground Monitor (GM) with a fully programmable digital Ground Fault Relay (GFR), all in a single compact package. 4DZ TechnologyTM (Patented) provides the most sophisticated, best performing Ground Monitor system available.   

To download the spec sheet click here.
To download the users manual click here.  

The GMS-504DZ includes an accessory port compatible with Intermountain Electronics expansion modules. These expansion modules (available separately) can be easily installed to dramatically increase interconnectivity and signal monitoring capabilities. For more information, see the Expansion Modules Page.

GMS-504DZ Accessories




1100-4001 Remote Control

1100-0006 /

Pilot Wire Device

Ground Monitor CT

1100-6010 GWD


1100-1920 GMS-540DZ 
Rear-Mount Adapter


HVGM-1 High Voltage Ground Monitor

The HVGM-1 is an impedance-type Ground Monitor (GM) designed to monitor the integrity of the grounding conductor between a power
source and equipment being powered.  

The HVGM-1 continuously monitors the impedance of the ground conductor.  If this impedance increases by 3 ohms from its calibrated level, the HVGM-1 trips.  

The HVGM-1 is designed for use in power systems in High-Voltage (HV) systems (over 1000V).  For LV or MV systems (under 1000V), IE recommends the GLT-500 and GMS-504DZ ground monitors.  

To download the spec sheet click here.
To download the users manual click here. 

1100-1100-MK1: HVGM-1 with Mounting Kit

1100-1100-MK1 is an HVGM-1 integrated with a mounting kit designed to simplify replacement of certain obsolete ground monitors. This mounting kit makes the HVGM-1 a direct replacement, with the same mounting holes and pin-out.

Ordering Information

Ground monitors

 Model Part # Description 
 GMS-504DZ 1100-1050

GMS-504DZ Ground Monitor / Ground Fault Relay

 HVGM-1 1100-1100 High Voltage Ground Monitor for systems over 1000V
 HVGM-1 w/
Mounting Kit
1100-1100-MK1  HVGM-1 w/ Mounting Kit for legacy GM replacement


Part # Description
 1100-6010 Optional Ground Wire Device (GWD) for GMS-504DZ, coil -type, requires 2000-1367 CT  
 2000-1367 Optional Ground Monitor Current Transformer, required when 1100-6010 GWD is used
 1100-6021 Optional Ground Wire Device (GWD) for GMS-504DZ, diode-type, w/ integrated 2000-1367 CT  
 1100-0006 Ground Fault Relay Current Transformer, 2.5" ID
 1100-0007 Ground Fault Relay Current Transformer, 4.2" ID
 1020-0052 Pilot Wire Device (included with the GMS-504DZ)
 1100-7100 Optional Expansion Module (compatible with GMS-504DZ) w/ D-Sub and 2-pin Barrier Strips)
 1100-7110 Optional Expansion Module (compatible with GMS-504DZ) w/ two 2-pin Barrier Strips)