smart gauge

[mikevye]

Does anyone know of a wiring diagram to install an audible alarm onto my smart gauge please. I've contacted Merlin who said they would send one but surprise they haven't.

 

regards mike

[WotEver]

Hi Mike,

 

The alarm outputs on the SG are just a set of relay contacts; NO, COM and NC. When the SG alarm status is off, then COM is connected to the NC contacts. When the alarm triggers then COM connects to the NO contacts and disconnects from the NC contacts.

 

 

Which connections you use depends on your alarm, but let's assume you've bought a simple 12V buzzer. You'd connect one side of the buzzer to 12V +ve and the other side of the buzzer to the NO terminal. You'd then connect the COM terminal to earth.

 

Alternatively, you'd connect one side of the buzzer to earth, the other side to NO and then connect the COM terminal to 12V +ve. Either way is ok, it makes little difference.

 

Don't forget to include a suitable fuse.

 

Cheers,

Tony

Edited September 6, 2013 by WotEver

[Justme]

What sort of alarm are you wanting to fit?

 

Very simply you would use the NO COM NC to trigger a relay to power the alarm. The alarm would not be powered direct from the SG unit.

 

(NO Normaly Open, COM Common, NC Normally Closed)

 

So with a standard relay you would use the NO & COM to trigger the relay.

 

 

Edit to add.

 

Tony beat me to it but has not used an external relay in his description. That might work in a low current device but using an external relay would help protect the SG relay from over loading.

 

 

From the manual

 

 

These three terminals are totally isolated from the rest of SmartGauge which means you can use them for

more or less anything within the following constraints:-

1. The maximum voltage between any of the three terminals and/or the DC system to which SmartGauge

is connected is 48 volts. Exceeding this voltage may damage SmartGauge, will invalidate the warranty,

will probably be in breach of any relevant safety regulations and may endanger life.

2. The maximum permissible current to be carried by the alarm terminals is 500mA (0.5 amps).

Exceeding this current may damage SmartGauge and will invalidate the warranty.

If either of these need to be exceeded then simply use the alarm output to operate an external relay with the

required specifications.

Edited September 6, 2013 by Justme