Add-On Ground-Fault and Earth-Leakage Modules

Class 931, 940, 960

MicroLogic™ Add-on Ground-Fault Module (GFM)

GFM250 with Optional GFM25CT

The MicroLogic Ground-Fault Module (GFM) is a UL Listed/CSA Certified circuit breaker accessory which protects equipment from damage caused by ground faults. It is an add-on module which, when connected to a PowerPacT H- or J-frame thermal-magnetic circuit breaker only, provides ground-fault sensing and ground-fault relay functions.

HD/JD ground-fault modules feature:

  • Adjustable ground-fault pickup levels

  • Adjustable ground-fault time delays

  • Integral ground fault push-to-test feature

  • Ground-fault indicator (mechanical for local, contacts for remote)

  • All GFMs are supplied for I-Line™ mounting as standard, easily convertible to unit mount by removing the I-Line bracket

  • Fault-powered (through the sensing current transformer) for electronics, shunt trip, and integral test feature. Meets NEC 230.95(C)

  • A 12 Vdc shunt trip module (Catalog No. P29382) is required in the circuit breaker. This may be field installed or factory installed when the circuit breaker is ordered with an -SN suffix.

  • UL 1053 — Ground-fault Sensing and Relaying Equipment

The GFM system requires the following:

  • H-frame (15–150 A) or J-frame (150–250 A) molded case circuit breaker

  • Shunt trip is required for the function of the GFM (may be factory-installed or field-installed)

  • Bus bar connection (terminal nut inserts) for OFF end of circuit breaker

  • Optional neutral current transformer, catalog number GFM25CT (must be ordered for 4-wire applications).

    note

    Ground-fault modules cannot be used for alarming only.

Module/Enclosure Selection Chart [1]

Companion Circuit Breaker Prefix

Cat. No. [2]

I-Line
Switchboard

Ground-fault Pickup
Adjustment Range

HD, HG, HJ, HL

GFM150HD

LA

20–100 A

JD, JG, JJ, JL

GFM250JD

LA

40–200 A

Accessories

H & J

GFM25CT

Optional Neutral Current Transformer (required for 4-wire loads)

Earth Leakage Module (ELM) for PowerPacT H- and J-Frame MCCBs

I-Line J-Frame with ELM Installed

The Earth Leakage Module (ELM) is an add-on module which, when connected to a PowerPacT H- or J-frame MCCB, provides low-level ground-fault sensing and ground-fault relay functions.

Because these ELMs are highly sensitive (30 mA to 3 A), they provide much greater protection than GFMs (20 to 200 A sensitivity). The ELMs provide greater protection of control circuits and other sensitive equipment. The associated circuit breaker must have a 48 Vdc shunt trip, which may be field-installed (kit P29392) or factory-installed (suffix –SP) in the H- or J-Frame circuit breaker.

Add-on Earth Leakage Module (ELM) Features:

  • Adjustable ground-fault pickup levels as low as 30 mA

  • Adjustable ground-fault time delays from instantaneous to 500 msec
    (Time delay can be applied to the 30 mA setting)

  • Integral ground fault push-to-test feature

  • Ground-fault indicator; pop-up button for local status and contacts for remote indication (to be used only with the tripping option)

  • All ELMs are supplied for I-Line™ mounting and are easily convertible to unit-mount by removing the I-Line brackets

  • Three poles; 240 to 600 Vac maximum: 3-wire applications only (no neutral)

  • Line-power obtained through internal bus to provide power for electronics, shunt trip, and integral test feature.

  • A shunt trip is required in the circuit breaker; it may be field-installed or factory-installed in the PowerPacT H and J circuit breakers.

  • UL 1053 – Ground-fault Sensing and Relaying Equipment

ELM Selection Chart [3]

Companion Circuit Breaker [4]

Enclosure Space Required I-Line Switchboard

Pick-Up Adjustment Range

Catalog Number

Prefix

Size

HD, HG, HJ, HL

15–150 A

LA

30 mA–3 A

ELM150HD

JD, JG, JJ, JL

150–250 A

LA

30 mA–3 A

ELM250JD

Footnotes

  1. At 250 A, the GFM250JD can be used with 80% rated circuit breakers only.
  2. See Supplemental Digest Section 3 for additional GFMs.
  3. At 250 A, the ELM250JD can be used with 80% rated circuit breakers only.
  4. For Factory Installation of ELM Module: For termination designation (3rd letter of catalog number) use ONLY “M”. Add factory installed 48 Vdc shunt trip (suffix SP) to breaker plus suffix VL or VM.

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