OEX ACX1941RBL Mini Relay 12V Change Over 30/40A - Resistor Protected, Sealed

OEX ACX1941RBL 12V Change Over SPDT Mini Relay 30A NC and 40A NO Resistor Spike Protection IP67 Sealed Single Unit

The OEX ACX1941RBL is a 12V change over (SPDT) mini relay with resistor spike protection, supplied as a single unit. Unlike a normally open relay, the change over configuration provides both a normally open (NO) and a normally closed (NC) contact, allowing it to switch between two circuits making it the correct choice for applications requiring circuit routing or polarity reversal. Dual current rating of 30A (NC contact) and 40A (NO contact). Silver tin oxide contacts, IP67 sealed housing and a removable mounting tab. Covered by a one year warranty.

Product overview

A change over (SPDT) relay has three switching terminals a common (30), a normally closed contact (87a, active at rest) and a normally open contact (87, active when energised). This allows the relay to route a circuit between two different paths depending on whether the coil is energised, which is something a standard normally open relay cannot do. Typical applications include dual circuit switching, polarity reversal, interlock circuits and any application where a circuit needs to be confirmed in a known state at rest.

The dual current rating of 30A on the NC contact and 40A on the NO contact is standard for change over relays where contact ratings differ between positions. Always confirm the circuit current against the rating for the specific contact position being used. The resistor spike protection suppresses the voltage spike generated when the relay coil is de-energised. The IP67 sealed housing provides full protection against dust and temporary water immersion for underbonnet and exposed mounting.

Features and benefits

Change over (SPDT) contacts: Provides both normally open and normally closed switching in a single relay, allowing the circuit to be routed between two paths depending on the coil state.

30A (NC) and 40A (NO) dual rating: The normally closed contact is rated at 30A and the normally open contact at 40A. Confirm the circuit current does not exceed the rating for the contact position being used.

Resistor spike protection: Suppresses the voltage spike generated when the relay coil is de-energised, protecting sensitive electronics and ECU outputs in the triggering circuit.

IP67 sealed housing: Fully protected against dust and temporary water immersion, suited to underbonnet, exposed and marine-adjacent mounting positions.

5 blade terminals standard ISO mini relay footprint: Compatible with standard mini relay sockets and harnesses. On a change over relay all five terminals are active.

Silver tin oxide contacts: Reliable switching performance with excellent contact life.

Removable mounting tab: Flexible installation options for panel and bracket mounting.

Single unit: For individual installations or replacements.

One year warranty: Covered by a one year OEX warranty.

Technical specs

Frequently asked questions

What is a change over relay? A change over relay (SPDT Single Pole Double Throw) has three switching terminals: a common (terminal 30), a normally closed contact (terminal 87a connected when the relay is at rest) and a normally open contact (terminal 87 connected when the relay is energised). This allows the relay to switch a circuit between two different paths depending on whether it is energised or not.

What does the 30A and 40A dual rating mean? The normally closed (NC) contact is rated at 30A and the normally open (NO) contact is rated at 40A. This is standard in change over relays where contact ratings differ between positions. Ensure the circuit current does not exceed the rating for the contact position being used.

How does this differ from the normally open ACX1940RBL? The ACX1940RBL is a normally open relay it has one switching contact that is open at rest and closes when energised. The ACX1941RBL is a change over relay with both a normally open and a normally closed contact, allowing it to route a circuit between two paths. Select the change over relay when you need to switch between two circuits or when a known circuit state at rest is required.

What is the standard mini relay terminal layout for a change over relay? The 5-blade mini relay uses the standard ISO layout: 85 (coil negative), 86 (coil positive), 30 (common), 87 (normally open active when energised) and 87a (normally closed active at rest). On a change over relay all five terminals are active, unlike a normally open relay where 87a is unused.

Is this relay suitable for underbonnet use? Yes. The IP67 sealed housing provides full protection against dust and temporary water immersion, making it suitable for underbonnet, exposed and marine-adjacent mounting positions.