Omron G7SA-3A1B — 4-Pole Safety Relay, 3 NO + 1 NC
SKU: G7SA-3A1BUSD 8.25
G7SA safety relay with forced-guided 3PST-NO + SPST-NC contacts, 6 A at 250 VAC, 24 VDC coil, for P7SA-10F socket.
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Product Overview
The Omron G7SA-3A1B is the 4-pole (3PST-NO + SPST-NC) version of the G7SA safety relay family. The forced-guided contact mechanism per EN 50205 / Class A VDE means the NO and NC contacts are mechanically linked -- a welded NO contact cannot leave the NC contact in a wrong state. That is the certification that lets the relay contribute to a Cat 1 / PL c up to Cat 3 / PL d interlock when paired with the right safety controller and dual-channel wiring. The 6 A / 250 VAC and 6 A / 30 VDC resistive contact rating handles typical contactor and solenoid coils in a 24 VDC cabinet.
Coil and timing
The 24 VDC coil draws 15 mA on 1,600 ohm coil resistance -- a standard 24 VDC control-rail output from a CP1 / CP2 / CJ PLC or a dedicated 24 VDC PSU can drive it directly. Operate voltage is 75% of rated or less (so the relay picks up on 18 VDC or less), drop-out is 10% of rated or more (so it releases cleanly when the coil falls below 2.4 VDC). Operate time is 20 ms or less, response time 10 ms or less. Mechanical life is 10 million operations and electrical life is 100,000 operations at the rated load.
The socket is required
The G7SA-3A1B is the bare relay -- it needs the P7SA-10F socket (10-pin, 4-pole) for panel or DIN-rail mounting. The P7SA-10F is the screw-terminal socket, the P7SA-10F-ND adds an action indicator LED, and the P7SA-10F-ND-PU DC24 is the Push-In Plus terminal version for faster wiring. The 14-pin P7SA-14F socket fits the 6-pole G7SA-5A1B / G7SA-4A2B / G7SA-3A3B siblings, NOT the 3A1B.
Before ordering
Confirm the coil voltage is 24 VDC -- the 3A1B also ships in 12, 18, 21, 48, and 110 VDC. Confirm the socket is on order: the bare relay is useless on its own. For the upstream safety controller, the G9SA-301 handles up to Cat 4 / PL e dual-channel with one G7SA-3A1B downstream; the G9SP-N20S is the standalone safety PLC option.
Key Features
- G7SA-series 4-pole plug-in safety relay with forced-guided contacts per EN 50205 / Class A VDE
- 3PST-NO (3a) + SPST-NC (1b) contact arrangement, 4 poles total
- 6 A at 250 VAC / 6 A at 30 VDC resistive contact rating
- 2 A at 240 VAC AC-15, 1 A at 24 VDC DC-13 inductive rating
- 24 VDC coil at 15 mA nominal, 1,600 ohm coil resistance (also 12 / 18 / 21 / 48 / 110 VDC)
- Operate voltage 75% of rated or less, release voltage 10% of rated or more
- 20 ms or less operate time, 10 ms or less response time, 20 ms or less release time
- 10 million mechanical operations / 100,000 electrical operations minimum
- Requires the P7SA-10F socket (sold separately) -- bare relay cannot be panel-mounted
- -40 to +85 C operating, 5 to 85 % RH, ~17 g, EN 50205 / VDE certified
- SKU: G7SA-3A1B
- Series: G7SA-3A1B
- Voltage: 24 VDC
Best-Fit Applications
- Guard-door interlock output relay downstream of a G9SA-301 or G9SP-N20S safety controller
- E-stop output relay in a Cat 1 / PL c or Cat 3 / PL d interlock circuit
- Contactor coil driver where the safety controller output needs higher current than the controller can supply
- Two-hand control output relay on a press or punch machine
- Light curtain output relay where the controller has no spare output channels
Buying Checklist
- Pick G7SA-3A1B for a 4-pole forced-guided safety relay with 3 NO + 1 NC, 6 A contact rating, and 24 VDC coil.
- Pick G7SA-2A2B DC24 instead when the application needs 2 NO + 2 NC contacts in the same 4-pole body.
- Pick G7SA-5A1B DC24 when a 6-pole (5 NO + 1 NC) safety relay is required -- needs the P7SA-14F 14-pin socket.
- Pick the P7SA-10F socket (M3 screw terminal) or the P7SA-10F-ND (with action indicator LED) -- REQUIRED for panel mounting.
- Pick the P7SA-10F-ND-PU DC24 for the Push-In Plus terminal version (faster wiring, no screwdriver).
- Pair the G7SA-3A1B with a G9SA-301 for a typical Cat 1 / PL c to Cat 3 / PL d interlock; pair it with a G9SP-N20S for a configurable safety PLC.
Technical Specifications
| Contact Form | 3PST-NO (3a) + SPST-NC (1b) -- 4 poles, forced-guided |
|---|---|
| Contact Rating | 6 A at 250 VAC / 6 A at 30 VDC resistive |
| Inductive Rating | 2 A at 240 VAC AC-15 / 1 A at 24 VDC DC-13 (IEC 60947-5-1) |
| Coil Voltage | 24 VDC (also 12 / 18 / 21 / 48 / 110 VDC) |
| Coil Current | 15 mA at 24 VDC, 1,600 ohm coil resistance |
| Operate / Release | Operate 75% of rated or less / release 10% of rated or more |
| Operate Time | 20 ms or less |
| Response Time | 10 ms or less |
| Release Time | 20 ms or less |
| Mechanical Life | 10,000,000 operations minimum at 36,000 ops/h |
| Electrical Life | 100,000 operations minimum at rated load, 1,800 ops/h |
| Operating Temperature / Weight | -40 to +85 C (12-48 VDC), 5-85% RH, ~17 g |
Resources & Downloads
FAQ for G7SA-3A1B
Does the G7SA-3A1B need a socket?
Yes. The G7SA-3A1B is the bare 4-pole relay with ten pins -- it needs the P7SA-10F socket (M3 screw terminal) or the P7SA-10F-ND (with action indicator LED) for DIN-rail or panel mounting. The P7SA-10F-ND-PU DC24 is the Push-In Plus terminal version for faster wiring. The PCB back-mount socket is the P7SA-10P. Without a socket, the bare relay cannot be wired into a control cabinet. Order the socket and the relay together.
What is the difference between G7SA-3A1B and G7SA-2A2B?
Contact arrangement. The G7SA-3A1B is 3PST-NO + SPST-NC (three normally-open and one normally-closed contact, four poles total). The G7SA-2A2B is 2DPST-NO + 2DPST-NC (two normally-open and two normally-closed, also four poles). Both use the same P7SA-10F socket, the same 6 A contact rating, and the same forced-guided EN 50205 certification. Pick the 3A1B when the safety output needs more NO contacts; pick the 2A2B when the application needs equal NO and NC contacts for mirror-contact monitoring.
Can the G7SA-3A1B reach Cat 4 / PL e by itself?
No. The G7SA-3A1B is a single 4-pole relay with forced-guided contacts. The safety category is set by the wiring, the input device, and the contactor monitoring -- not by the relay alone. For a Cat 1 / PL c interlock, wire the G7SA-3A1B's NC contact in series with the contactor coil. For a Cat 3 / PL d interlock, use two channels of input with cross-monitoring and a G9SA-301 or G9SP-N20S safety controller upstream of the G7SA-3A1B. The G7SA-3A1B provides the certified direct-opening contacts needed to support a Cat 1 / PL c or Cat 3 / PL d circuit, but it does not claim those categories on its own.
Is the G7SA-3A1B the same as a G7S-3A1B?
No. The G7SA is the slim plug-in safety relay family with forced-guided contacts per EN 50205 / Class A VDE, 6 A contact rating, 10 million mechanical operations. The G7S is the older safety relay family with a larger case and lower contact rating. The G7SA is the current pick for new builds; the G7S is typically encountered as a like-for-like replacement on existing panels. The P7SA socket is the G7SA socket; the G7S uses a different P7S socket. Verify the model code on the existing relay before ordering the replacement.
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