3 Phase Motor - Fault Indicator

Thread Starter

majsyd2010

Joined Aug 29, 2010
61
Good Day Guys …
I must say that love this website and all these helpful forums.
My question! Is there any way of creating an indication lamp if the motor lost its supply phase using really or contactor, For example Blue phase supply fuse blown to the motor, and if that happen, the fault light indicate.
See what you guys come with
Cheers
 

Kermit2

Joined Feb 5, 2010
4,162
Good Day Guys …
I must say that love this website and all these helpful forums.
My question! Is there any way of creating an indication lamp if the motor lost its supply phase using really or contactor, For example Blue phase supply fuse blown to the motor, and if that happen, the fault light indicate.
See what you guys come with
Cheers
Current sensing relays are common in industrial applications. They sense the flow of current and either tell you it has stopped or when it has gone above or below a threshold.

Implementing something to sense the current in the phases should be pretty straight forward. Are you looking for a commercial product to do this? Honeywell makes hundreds of models and types for AC or DC currents ranging from a single amp to thousands of amps. Both mechanical and solid state, open loop, or closed loop.

Google current relay and look for honeywell, they have a multipage pdf outlining their product line.
 

timrobbins

Joined Aug 29, 2009
318
I suggest a cheaper and simpler solution is a 'phase failure' relay - it is put across the motor input, and if a phase fuse fails, or a phase voltage drops below a certain relative percentage compared to the other phases, then it activates.

Ciao, Tim
 

BillB3857

Joined Feb 28, 2009
2,570
Take a look at this ....... http://www.squared.com/us/products/relays_timers.nsf/unid/D19099054747188A85256CB60056D979/$file/phaselossrelays.htm
 

Pich

Joined Mar 11, 2008
119
The easiest way would be to connect the lights across the fuses, of course lights would need to be the same voltage as the supply voltage.
 

Thread Starter

majsyd2010

Joined Aug 29, 2010
61
Pich ... You give me the cheapest and easy way and belive it or not, I am doing it right now.

I keep saying that love this forum .. Keep learning and learning
 

marshallf3

Joined Jul 26, 2010
2,358
Yea, and believe it or not good old panel mount Neon indicators are great for this. They usually come with an integral resistor for 120V but it's easy enough to add to that if your source is 408Y/277

I personaly like the green ones but they'd be best on the load end of the fuses to neutral since they'd indicate all is OK, you'd probably want the orangish-red ones if you used them across a fuse to indicate a dropped phase.
 

Thread Starter

majsyd2010

Joined Aug 29, 2010
61
I used the green last night and work perfectly great as what I want. I am keep say this that you gotta love this website. what a wonderful forum ....
 
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