Allen-Bradley 440R-N23135 Guardmaster MSR127RP Safety Relay, 24V AC/DC, 3NO 1NC
Allen-Bradley 440R-N23135 is a Guardmaster single-function safety relay (type MSR127RP) that monitors guarded machines with a 24 V AC/DC control supply, providing three normally open safety outputs and one normally closed auxiliary output.
Overview
The 440R-N23135 accepts inputs from one normally closed guard door switch, two normally closed contacts or a light curtain, and requires a monitored manual reset before the machine may restart. Its 22.5 mm wide removable-screw housing clips to a 35 mm DIN rail, accepts wire up to 4 mm², and carries an IP40 enclosure rating for panel mounting.
Key Features
- Single-function safety relay, type MSR127RP (Guardmaster family)
- 24 V AC/DC rated control supply, 50/60 Hz
- 3 normally open (N.O.) immediate safety outputs + 1 N.C. auxiliary output
- Monitored manual reset for controlled restart
- Input contact: 1 N.C., 2 N.C. or light curtain
- Removable screw terminals; wire size up to 4 mm²
- 22.5 mm enclosure width; IP40; 35 mm DIN rail mount
Technical Specifications
| Attribute | Value |
|---|---|
| Manufacturer | Allen Bradley (Rockwell Automation) |
| Product Line | Guardmaster Safety Relays (440R) |
| Part Number / Catalog No. | 440R-N23135 |
| UPC | 611320806526 |
| Product Type | Single-Function Safety Relay (MSR127RP) |
| Rated Supply Voltage | 24 V AC / 24 V DC, 50/60 Hz |
| Safety Outputs | 3 N.O. (immediate) |
| Auxiliary Outputs | 1 N.C. |
| Delayed Safety Outputs | Not Installed |
| Reset Type | Monitored Manual Reset |
| Input Contact | 1 N.C., 2 N.C. or Light Curtain |
| Contact Rating | AC15: 250 V 5 A / DC13: 24 V 3 A |
| Enclosure Width | 22.5 mm |
| Terminals | Removable Screw Terminals |
| Wire Size | 4 mm² maximum |
| Mounting | 35 mm DIN Rail |
| IP Protection | IP40 |
| Dimensions | 13 x 13 x 4 cm (5.1 x 5.1 x 1.6 in) |
| Weight | 0.56 lbs (0.26 kg) |
Applications
The 440R-N23135 is the standard choice for single-zone machine guarding: interlocked guard doors on conveyors, packaging machines and presses, or light-curtain protected access points where a supervised manual reset is required before restart.
Why Buy from Us
This safety relay is available new in original factory packaging, fully tested and backed by a standard warranty of 1 year. We ship worldwide with careful protective packaging and fast dispatch. Quantity discounts and repair/exchange options are available on request.
Documents
| Resource | Title | Link |
|---|---|---|
| Publication | 440R-IN079 — MSR127T / MSR127TP / MSR127R / MSR127RP Safety Relays Installation Instructions (English) | 440r-in079_-en-p.pdf |
| Publication | 440R-TD001 — Guardmaster Safety Relays Technical Data (English) | 440r-td001_-en-p.pdf |
| Data Sheet | MSR127RP Safety Relay Specification Sheet | MSR127RP.PDF |













