General Installation Method of Induction Motors

Prior Installation:

• Check the insulation resistance of the windings for phase / earth and values to be greater than 10MΩ
• Ensure the bearings are working correctly

Mechanical Installation:

1. Installation must be performed by qualified / manufacturer recommended personnel.
2. Installation to be done on environment as specified by manufacturer.
3. Lifting of motor to be carried with lifting rings  and mounting to be done on position (on a firm, levelled to avoid vibration).
4. Mechanical connections to be ensured.

Electrical Installation:

1. Cables must be terminated by trained personnel with power off.
2. Tighten the nuts of terminals, connectors and supply cables as recommended by manufacturer.
3. Connect according to name plate and diagram details in terminal box and check direction of rotation of motor.
4. Connect the thermal protection devices and all accessories.
5. Use specified cable gland suiting cable diameter and areas of application.
6. Confirm the earthing done as per required standards.

Commissioning:

• Motor speeds should not exceed the maximum speeds as recommended by manufacturer.
• Comply with supply parameters as mentioned in name plate details.
• Selection of motors requires particular construction specifications.

Maintenance of the motors to be carried out as per manufacturer recommendations and frequency of greasing the bearings and type of grease to be used. Ensure the environmental factors are as specified.

ATS (Automatic Transfer Switch) Panels.

For emergency power in residential and commercial buildings, an Auto Transfer Switch (ATS) is essential. The ATS can automatically transfer load from main power to emergency power without operator intervention. When the main power fails or voltage drop below 80% of normal voltage, the ATS will start the emergency generator, after a preset time of 0 to 10 seconds (adjustable). At rated speed, the ATS will transfer load to emergency power.

Types of ATS Panels:

ATS Motorized Type:
Automatic transfer switch consists of Motorized breaker (MCCB/ ACB) electrically and mechanically interlocked as per the regulations and standards of local Authorities. 

ATS Contactor Type:
Automatic transfer switch consists of 4 pole/ 3 pole contactors mechanically interlocked to transfer the load automatically. 

ATS Changeover Type:
Automatic transfer switch consists of Changeover (Automatic) 4 pole/ 3 pole motorized to transfer the load automatically along with the option of manual bypass.

American Scientist

Website Address: http://www.americanscientist.org

Language: English

Brief Notes:

• Science and Technology Magazine Website
• Its Bi Monthly Magazine consists of articles on Science and Technology.
• Regular topics covers Computing, Engineering, Public & Professional Issues.

Cathodic Protection

Cathodic Protection:

It is a method to control the corrosion of a metal surface by making it as a cathode of the electro chemical cell. In simple the metal to be protected is connected with piece of another sacrificial metal (anode of the cell).

Existing Switch gear Modification Tips

For Tie In of new connected load to the existing Switch Gear the following adequacy check and modifications to be verified.

1. Review the existing electrical load summary and necessary update to be done.
2. Review the existing Single Line Diagram of Switch Gears.
3. Carry out worst case scenario for Load Flow Analysis to ensure adequacy of existing switch gear, transformer and incoming feeders of existing switch gear to supply the new loads with specified steady state voltage drop limits.
4. Carry out worst case scenario for Short Circuit Calculation to ensure new fault level is with in the Switch Gear short circuit ratings.
5. Upgrade any electrical component of the existing substation / distribution system to supply the new load.
6. Modify existing protection relay settings to ensure proper co ordination with the new installation.
7. Modify all affected existing drawings to As Built to reflect the new connected load.