How to Connect An External Device to the C-Form Relay on the ERA-DCRX
*Please note, in most cases it is sufficient to use the 12V DC outputs to connect an external device to the system. For these instructions on this process, click here.
Each ERA-DCRX receiver has 1 x C-form relay for integrating and connecting external devices. Unlike the 12V DC outputs (1 per zone) on the receiver, the C-Form relay DOES NOT supply power to the external device you are connecting to it.
Why Use the C-Form Relay?
The C-Form relay offers advantages and flexibility the 12V DC outputs do not offer. For example, with the 12VDC output, the device you are powering has to be rated for 12V or less. In addition, the external device you are connecting has to have a max current below 400mA. This is not the case with the C-Form relay as it does not supply the power but rather functions more like a switch.
Another advantage of the relay is that it's not limited to one zone. There are dip-switches on the ERA-DCRX that allows you to associate the device on the C-Form relay with any combination of the four zones. Let's say, for example, you have to push buttons, one for zone one, and another for zone two. You might want to put a different colored strobe light on each of these zones. Red on zone one and blue on zone two. Push button A triggers the zone 1 melody and the red strobe, and push button B triggers the zone 2 melody and the blue strobe. You like the fact that the strobes provide a good visual notification, but want something really loud. Using the C-Form relay, you add a loud siren or fire bell to also trigger when one (or both) of the push buttons are pressed.
How to Connect an External Device to the C-Form Relay
In this example, we are going to connect a 12V DC fire alarm bell to the relay and make the assumption you already have a push-button programmed to zone one (1). The C-Form relay will only be activated when a transmitter, programmed to zone 1, is triggered.
1) Make sure plug-in transformer is NOT plugged in and ERA-DCRX receiver is NOT plugged in.
2) The next step is to associate the C-Form relay with a zone(s). Reference the small dip switches in "fig 2" in the drawing below. Set dip switch 1 up, and ensure 2, 3, & 4 down. This setting associates the C-Form relay with zones 1.
3) Set duration time. Set the drip switches per the drawing in "fig 1." This will determine how long the external device will turn on.
4) Connect black wire from fire bell to the "NO" terminal screw on section labeled "relay."
5) Connect red wire from fire bell to left terminal screw on plug-in transformer.
6) Use a wire to connect right terminal screw on the plugin transformer (ignore the center screw on transformer) to the "COM" terminal screw on the ERA-DCRX output section labeled relay.
7) Plug everything back in and start using!
