I am looking for some alarm PIR sensors that will operate on a 24v DC supply
for use on a double-decker bus that is being converted to a Men’s Shed
workshop. The standard bus supply is 24v and the alarm contacts would need
to be either N/O or N/C

as the alarm control panel does not use EOL resistors.

Please could you suggest some suitable devices.

Is this internal or external detection

 

But if your using a control panel is this not 12v?

This is for internal detection.

The alarm controller is designed for a commercial vehicle that runs on a 24v supply.  The supplied sensors are ultrasonic intended for use in the confined space of a truck cab and therefore not suitable for the wide space on a bus with draughts around the doors. The alarm box has auxiliary connections for normally open or closed contacts which the manufacturer has advised could be used with a regular internal PIR that will operate on a 24v supply (but they do not supply)

Just use a low cost dc-dc converter to step 24v down to 12v. Easier than sourcing 24v sensors.

Agreed I'd look at that even takex max at 18v

You could use optex redwall sensors but they are an external detector. As Selfmon says I'd look to convert down