9-8. Power Required To Start Motor

4

 

 

AC MOTOR

 

2

1

 

 

 

 

VOLTS

230

AMPS

2.5

 

 

 

 

 

3

 

CODE

M

Hz

60

 

 

 

HP

1/4

PHASE 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Single-Phase Induction Motor Starting Requirements

Motor Start

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Code

G

 

H

 

J

K

L

M

 

N

 

P

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

KVA/HP

6.3

 

7.1

8.0

9.0

10.0

11.2

 

12.5

 

14.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

kVA/HP x HP x 1000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

= STARTING AMPERAGE

 

 

 

 

 

 

 

VOLTS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

EXAMPLE: Calculate the starting amperage required for a 230 V, 1/4

 

 

HP motor with a motor start code of M.

 

 

 

 

 

 

 

Volts = 230

HP = 1/4 Using Table, Code M results in kVA/HP = 11.2

11.2 x 1/4 x 1000

= 12.2 A

Starting the motor requires 12.2 amperes.

 

230

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1Motor Start Code

2Running Amperage

3Motor HP

4Motor Voltage

To find starting amperage:

Step 1: Find code and use table to find kVA/HP. If code is not listed, multiply running amperage by six to find starting amperage.

Step 2: Find Motor HP and Volts.

Step 3: Determine starting amper- age (see example).

Welding generator amperage out- put must be at least twice the motor’s running amperage.

S-0624

9-9. How Much Power Can Generator Supply?

1

2

1Limit Load To 90% Of Generator Output

Always start non-resistive (motor) loads in order from largest to small- est, and add resistive loads last.

2 5 Second Rule

If motor does not start within 5 seconds, turn off power to prevent motor damage. Motor requires more power than generator can supply.

Ref. ST-800 396-A / S-0625

OM-486 Page 36

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Miller Electric 251 NT manual Power Required To Start Motor, How Much Power Can Generator Supply?, KVA/HP x HP x
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251 NT specifications

The Miller Electric 251 NT is a highly regarded multi-process welding machine known for its versatility and advanced features, making it an ideal choice for professionals in various industries. With its robust construction and user-friendly interface, the 251 NT provides an efficient solution for MIG, TIG, and Stick welding applications.

One of the main features of the Miller Electric 251 NT is its impressive output range, which allows for welding on a variety of materials and thicknesses. It delivers up to 250 amps of power, enabling users to tackle both thin and thick metals with ease. Additionally, the machine is equipped with an Auto-Set feature, which automatically adjusts the welding settings according to the material thickness and type. This eliminates the guesswork, significantly enhancing productivity and reducing setup time.

Another noteworthy aspect of the Miller Electric 251 NT is its inverter technology. This advanced technology provides a compact, lightweight design without compromising performance. Inverter technology allows for greater energy efficiency, resulting in reduced operational costs over time. The 251 NT also features a Duty Cycle of 60% at 250 amps, which means it can handle demanding tasks while maintaining optimal performance.

The Miller Electric 251 NT is designed with user convenience in mind. The intuitive digital display offers clear visibility of the settings, allowing welders to make quick adjustments. Furthermore, the machine includes a built-in memory function to store frequently used parameters, enhancing workflow efficiency.

Safety is a key component of the 251 NT's design. It comes equipped with various safety features, including overload protection and a thermal overload warning system. These features ensure that the machine operates within safe limits, minimizing the risk of damage and ensuring longevity.

In terms of portability, the Miller Electric 251 NT's lightweight design and integrated handle make it easy to transport between job sites. The durable housing protects the internal components, making it suitable for rigorous use in demanding environments.

Overall, the Miller Electric 251 NT offers a combination of power, flexibility, and ease of use, making it a top choice for welders looking to enhance their capabilities across multiple welding processes. Whether in a professional shop or on a construction site, the 251 NT stands out as a reliable and efficient welding solution.
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