Standby motor

hello guys,I would really appreciate it if you could help me... I have one set of motor ie, one working and one standby,my doubt is,whether it has two power circuits and two control circuits...then how its connected to load?Can we use selector switch for selecting standby motor....please help me also I'm a beginner....

typically a stand by motor win have its own seperate power and Control feeds, but I am not there to verify that.
Also typically there will be either a selector to run it, or if main faults standby will start automatically. other scenarios such as low pressure on a pump can cause the standby to start as well.

When we have Duty/Stand By, we use two fuses/contactors/converters etc. In case of failure on the duty motor, we switch to the stand by.

Sometimes we switch when pressure is low (for circulation pumps). Or start the standby pump in addition to duty pump (for feed water pumps).

I don't think you can call it a Stand By pump if you have a manual selector switch.

If I understand you question correctly, to be stand by, you should have an extra pump/load as well.

Do you have two motors connected to a single load, or two pieces of equipment. Boneless' question is on point.

Generally a standby is intended to allow maintaining process operation when a unit is out of service for maintenance or repair. As such it should have all of the devices needed to allow operation in that circumstance.

It is not good practice to never run standby equipment, since prolonged idleness will result in bearing damage from condensation, corrosion and loss of lubrication. Then when the standby is brought online early failure results. Most systems have the ability to alternate through the available equipment, either automatically or by means of operator selection, to avoid that.

Thanks to all....only one motor is connected to one load...but there is a separate motor,come under operation when main fails...My question is when main fails,want we rewire to standby motor??

I don't understand what you are saying Jill.

You have a stand by motor, not connected to the load and not wired? But you also say you have two power and control circuits?

Every time management gets involved they want me to program the standby systems to equalize the run time on each.
This way when one is worn out and fails the other is right behind it.
The guys at US Steel wanted their air mist compressors programmed this way and after the usual protest I did.
There were 15 of them and they all failed within a month of each other. Maintenance was very busy and the manufacturer had a heck of a time getting enough ot the SAME parts for all of them!