Description
Product Introduction
Feeder faults, ground-current events, and breaker operating problems can disrupt production and put downstream equipment at risk. The GE Multilin SR750-P1-G1-S1-HI-A20-R-E-H is a configurable feeder management relay designed for electrical protection, metering, monitoring, and control in industrial distribution systems. Its 1 A current inputs and eight 4–20 mA analog outputs support installations designed around those signal requirements.
The HI supply option accommodates a broad AC/DC control-power range, while E specifies the enhanced display and H adds the harsh-chemical-environment option. GE has discontinued production of the 750/760 family, so replacement planning should include firmware, settings, and retrofit considerations—not just the catalog number.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Model | SR750-P1-G1-S1-HI-A20-R-E-H |
| Manufacturer | GE Multilin |
| Relay family | 750 feeder management relay |
| Protection role | Feeder protection and management |
| Phase-current inputs | 1 A nominal |
| Zero-sequence current input | 1 A nominal |
| Sensitive-ground current input | 1 A nominal |
Control power (HI) |
88–300 VDC or 70–265 VAC, 48–62 Hz |
Analog outputs (A20) |
Eight channels, 4–20 mA |
Breaker-closed LED (R) |
Red |
Display (E) |
Enhanced display, larger LCD, improved keypad |
Environmental option (H) |
Harsh Chemical Environment option / conformal coating |
| Communications | Serial ports; optional Ethernet depends on the exact ordered configuration |
| Supported protocols | Modbus RTU and DNP 3.0 over serial; Modbus over TCP/IP requires the Ethernet option |
| Installation | Drawout relay and companion case for panel or rack mounting |
| Production status | Discontinued by GE; remaining stock and retrofit options may be available |
| Condition and warranty | Must be confirmed by supplier |
Specifications are based on GE’s published 750/760 documentation. Verify the relay nameplate and manual revision for the exact unit being purchased.
SR750-P1-G1-S1-HI-A20-R-E-H
Application Scenarios & Pain Points
A protection relay replacement can become a commissioning problem if the current-transformer ratings or programmed trip logic differ from the removed unit. This configuration is relevant to applications such as:
- Industrial distribution feeders: Phase and ground overcurrent protection for appropriately grounded electrical systems.
- Ground-fault monitoring: Separate zero-sequence and sensitive-ground inputs support protection schemes configured for the installed CT arrangement.
- Breaker control and monitoring: The 750 family supports trip/close control, breaker-failure logic, and breaker-condition monitoring.
- Power-system integration: Metering, event recording, and analog outputs can support plant monitoring and supervisory systems when configured for the application.
- Harsh industrial environments: The
Hoption is intended for harsh chemical environments; it does not remove the need to check enclosure conditions, wiring practices, and environmental limits.
Related Products
The following are relevant comparison points for replacement planning. They are not automatically interchangeable.
- GE Multilin 750-P1-G1-S1-HI-A20-R-E — Similar base configuration without the
Henvironmental option. - GE Multilin 750-P5-G5-S5-HI-A20-R-E — Related 750 configuration with 5 A phase, ground, and sensitive-ground inputs.
- GE Multilin 750-P1-G1-S1-LO-A20-R-E — Similar input/output arrangement but with the low-range control-power option.
- GE Multilin 750-P1-G1-S1-HI-A10-R-E — Similar configuration with eight 0–10 mA analog outputs instead of 4–20 mA.
- GE Multilin 750-P1-G1-S1-HI-A20-G-E — Related configuration with a green breaker-closed LED.
- GE Multilin SR760 — Related feeder management relay with autoreclose functionality; application and ordering codes differ.
- GE Multilin 850 — GE-identified alternative to consider when planning a replacement for the discontinued 750/760 series. Retrofit suitability must be engineered for the existing panel and protection scheme.
Engineer’s Guide: Replacement Checks
1. Match all three current-input ratings. Warning: P1, G1, and S1 specify 1 A inputs. A 5 A variant is not a direct substitute without confirming CT secondary ratings, relay configuration, and protection settings.
2. Confirm the complete control-power range. HI is the high-range supply option: 88–300 VDC or 70–265 VAC at 48–62 Hz. Check the actual station supply and wiring before energizing the replacement.
3. Check communications and the environmental suffix separately. Warning: E means enhanced display, not Ethernet. The documented Ethernet-enhanced option is T; verify the original unit’s communications hardware and the function of H before ordering.
Before commissioning, back up the original settings, document CT and VT ratios, review trip and close logic, and perform the site’s required secondary-injection and functional tests. Because the series is discontinued, also confirm firmware compatibility and whether the replacement includes the required drawout case or is supplied as a relay-only unit.
Frequently Asked Questions
Q1. What is the GE SR750-P1-G1-S1-HI-A20-R-E-H used for?
It is a feeder management and protection relay for electrical distribution systems. Depending on configuration and settings, the 750 family provides overcurrent protection, ground protection, metering, breaker control, and event monitoring.
Q2. Does this model use 1 A or 5 A current transformers?
The P1, G1, and S1 codes indicate 1 A phase, zero-sequence ground, and sensitive-ground current inputs. Verify each CT secondary rating against the installed protection drawings.
Q3. Does E mean the relay has Ethernet?
No. In GE’s published ordering scheme, E indicates the enhanced display. The T option indicates an enhanced display with 10Base-T Ethernet. Confirm the actual rear-panel connectors and communications configuration before connecting a network.
Q4. What is the function of the H suffix?
It denotes the harsh-chemical-environment option, associated with conformal coating. It should not be interpreted as a general certification for every corrosive, wet, or high-temperature installation.
Q5. Is the GE Multilin SR750 still manufactured?
GE’s current legacy product page states that manufacturing of the 750/760 series has been discontinued and identifies the 850 as an alternative to consider. Existing systems may still be maintained with available inventory, but replacement engineering and retrofit planning are important.
Q6. Can I replace this unit with another SR750 model?
Only after comparing CT input ratings, control-power range, analog output type, display and communications options, environmental option, firmware, and settings. A matching family name alone does not establish compatibility.
Q7. What should I confirm before buying a used or refurbished unit?
Request clear photographs of the nameplate and rear connectors, written confirmation of the complete order code, condition and test status, warranty terms, and whether the drawout case is included. For a discontinued relay, ask about firmware and settings compatibility before committing to the purchase.
