ac motors

Depends on what motor and configuration! Is it a 3 phase, single phase, star/delta start up, cheesie little 12Vac, Big brutal monster of a motor...etc...We need more info, and I don't mean 'yes, it's big!' either!

I'm talking of a 230V 3-phase delta connection (up to1200rpm, 0.75kW)

Suppose the feed lines cannot be identified, will there be any harm caused to the motor if Line 1 is connected to the W terminal,Line 2 to U terminal and Line 3 to V terminal (as oppossed to 1 to U, 2 to V and 3 to W) even if the motor runs in the desired direction?

If it's 3 phase, it will run backwards if connected wrongly. If it's single phase with two leads, then it will run correctly. More info needed otherwise.

I'm talking of a 230V 3-phase delta connection (up to1200rpm, 0.75kW)

Suppose the feed lines cannot be identified, will there be any harm caused to the motor if Line 1 is connected to the W terminal,Line 2 to U terminal and Line 3 to V terminal (as oppossed to 1 to U, 2 to V and 3 to W) even if the motor runs in the desired direction?

Nope -- just switch two of 'em.

Thanx!

I was worrying it might cause overheating

Hello Guest - yes, we've got the message by now!

Cheers.......Codey

I'm talking of a 230V 3-phase delta connection (up to1200rpm, 0.75kW)

Suppose the feed lines cannot be identified, will there be any harm caused to the motor if Line 1 is connected to the W terminal,Line 2 to U terminal and Line 3 to V terminal (as oppossed to 1 to U, 2 to V and 3 to W) even if the motor runs in the desired direction?

Don't run for long in reverse direction case the motor is not bidirectional (some times the cooling fan behind is not bidirectional)

Also the motor if connected to a pump may cause the pump to seize.

The usual procedure we follow is On/OFF and check the direction of rotation.

However if the motor runs in correct direction why bother (in time phase there is no RBY they are unifirmly distributed at 120 deg phase shift, and when in a circle one is behind other who is first ? a la in the second orbit around atom (classical theory not spdf orbitals or electron clouds ) of 8 electrons any one can be first , others wrt this are 2nd 3rd etc.