Safe-T-Cut

[tatom]

Here in Issan, many home fuse boxes consist of a knife switch and a breaker. (some are just a knife switch! Lately, new houses are installing real electric systems.)

Ive seen alot of people replacing thier knifeswitch-breaker system with a safe-t-cut, or just adding a safe-t-cut to the incoming line.

I would like to know if that is a big improvement and if so, why?

[lopburi3]

If the Safe-T-Cut is the RCBO model it is a big improvement as provides life saving protection by stopping current before it is more than a shock. These are the several thousand baht units. But Safe-t-cut also makes normal electrical breakers now so you have to be sure (look for test button and 10ma-30ma or such switch on them).

[prefabs]

Saves you from dying

[prefabs]

Saves you from dying

Sorry about that. I installed one recently 63Ampere rated was 3600 baht. Surely your life is worth more than 75 quid

[electau]

An RCBO ( otherwise known in Thailand as a Safe-T -Cut after the manufacturer) will disconnect supply in the event of an earth fault in less than 0.4secs.

They will operate with a high earth fault impedance, ie at 220VAC a 30mA the impedance may be up to 7333ohms, for 10mA the impedance is 22000ohms.

So in the event of a broken earth conductor and an earth fault (indirect contact) the RCD will operate below 30mA , the value where fillibration of the heart occurs. 10mA is the point where muscular contraction may occur and the inability to "let go". Muscular contraction may result in the inability to breathe.

In practice an RCD will trip in 20 to 30mS.

The RCBO will also provide overcurrent protection as it combines the function of an RCD and MCB.

The direct setting of the sensitivity switch on some units disconnects the RCD function so they do not comply with IEC standards.

The 5 mA range appears to comply with the NEC (US National Electrical Code) which permits RCD protection of 2 pin socket outlets.

　

Edited May 4, 2012 by electau

[tutsiwarrior]

look for the guy in a pick up truck with a loud speaker...that's where we got ours...the installer is a bit of a dolt and just watch him and check the circuits...

'safety cut!, safety cut!: whoooah safety cut!...' and tutsi now sleeps better at night...

(sounds like an LSD scenario but it ain't...my wife sez that it really happened...and there it is splendidly displayed on the wall where the circuit box useta be...)

Edited May 4, 2012 by tutsiwarrior

[cooked]

There are many electrocutions every year in Thailand, tourists included, Thais think it is normal to get a shock of fridges, computers and so on. They will earth electrical systems on to pvc pipes... etc. There exist apparatus to test if your system is earthed, I don't know how these work. Anyway, my brother in law is an electrician and he fixed up a safety cut system in his house in Kanchanaburi and reckons this is the way to go. Our house is on a circuit breaker set at 5mA and we test it now and then. When they installed the air conditioning they installed a mini circuit breaker as a matter of course which is a good idea.

Most Thai houses seem to be installed with two prong plugs anyway, so unless you want to redo the whole wiring, by someone that isn't colour blind and doesn't think 'in Thailand we not do' then this is probably the best way to go.