Computerize Motor Rewinding

//Computerize Motor Rewinding
Computerize Motor Rewinding 2017-08-20T18:31:37+00:00

When your motors need repair, count on ALPS MSI for efficiency improvement, quality, precision, and expert service – all backed by a 100% satisfaction guarantee.

We have the experienced & capabilities to restore motor efficiency, provide repair on-site or at our facility. We understand the complexities of AC and DC motor repair and will take the necessary steps to return your equipment to optimum working condition. Further, we offer testing of repaired motors to ensure the electrical and mechanical operation exceeds your expectations.

 

Case Study

One of the biggest medical center in Makati encountered problems in one of their vertical pumps.

The highest vibration level was measured at motor non-drive end with amplitude of 19.2 mm/s RMS.

They provided the current load only as follows: L1 = 17.6A; L2 = 19.7A; and L3 = 19.0

A with an average 18.77 Amps. Current load unbalance is 6.22% and is prone to single phasing if left unattended. Our offer was to rewind the motor with guaranteed minimum energy savings of 10%.

Motor specifications are: 15HP, 230V/460V, 41/20.70 Amp, PF 83.3, 3Ph, 60Hz, RPM 3505

Nominal Efficiency: 81.5%

Guaranteed Efficiency: 78%.

Let‘s use the following formula to calculate energy consume.

Equation 1:
% Motor Load = Ave. Actual Supply Voltage x Ave. Actual Amps x 100%
(Nameplate Voltage x Nameplate Full-Load Current)

Equation 2:
E = (Nominal x L x C x H)
η

Where:  E = Energy Consumed
P Nominal = Nominal Power
L = Motor Load, %. Refer to Equation 1
C = Cost of Energy, say ₱6.5/kWhr
H = Running hours, 6,400 hours
η = Efficiency, 78%

Calculations:

Referring to equation 1, %Motor load = 91%
Referring to equation 2, Energy consumed = ₱534,185.00 per year

Energy consumed = (9.6kW x 6,400 hours x ₱6.5/kWhr)
   = ₱399,776.00

The vibration level was reduced from 19.2 to 3.4 mm/s RMS. The annual savings is equivalent to ₱134,409.00 or 25%.

 Computerize Motor Rewinding Result

Why choose us to repair your motor?

Energy efficiency improvement is our way of life here at ALPS MSI. Improving motor efficiency after rewound is a challenge for us providing the value of your money. Efficient motor uses less energy.

A motor is manufactured with inherent losses due to quality of materials and design aspects. It is very important why in the process of motor rewinding (repair), said losses should be maintained or improved. However, there are motor losses that the service provider can’t maintain or improve. These are: a) Core loss, and b) rotor loss. Why?

  • Core loss. The core is made of permeability steel materials bind together to form laminations in the core. It has slots (stator) where magnet wires are inserted. The high quality of permeability steel materials played an important role in motor efficiency and demands higher price. Care in removing burnt magnet wires and insulating varnish using the proper methodology.

  • Rotor loss. The rotor is the moving component of the motor made of conductive bars and end rings to reduce resistance. Frequent start and stop of the motor will result to broken rotor bars, particularly for large HP rating motor. This is very difficult to repair and there is no guarantee of motor reliability.

Bearing failures that may result to damage rotor bars or stator core will definitely affect motor efficiency. Proper implementation of vibration analysis will help a lot preventing bearing failures.

You may probably experienced that after a new motor had been repaired, the cycle of burnt motor increases. We encourage our clients to provide us the full history of motor prior to breakdown to enable us analyze how to prevent another breakdown. Such as actual voltage supply, amperage, and vibration levels. Below are the causes:

ALPS MSI don‘t rely on the existing data of burnt motor and took higher step to verify using a rewinding software. 90% of burnt motors we received for rewind had insufficient number of turns/coil result or wrong winding data resulting to increase in energy consumption. Our software ensures the Circular Mil Amps (CMA) are suitable for motor specifications, and maintain or improve its efficiency.

The output of our software design is encoded to SAMATIC 8080 (computerize motor rewinding machine) to form the coils perfectly without any doubts. SAMATIC feeds and guides the wires inside every former slot in a precise layering, all done fully automatically. Coils are perfectly layer wound, are perfectly tensioned and have zero crossovers. This will make the FASTEST, EASIEST coil insertion into the narrowest motor slots.

The end result is the motor we rewound is more efficient and uses less power. This is the value we provide to our clients.

High vibrations or improper re-lubrication of bearings will stress the bearings forcing the motor to draw more energy, and increase motor winding and motor body temperatures. As motor body temperature increases, grease dried-up resulting to bearing failures.

Bearing failure affects interference fits of shafting or bearing housing, and clearances. We have the expertise and capabilities to ensure correct interference fits, and invested on professional bearing tools.

Insufficient motor fan ventilation also contributes to losses.

The vibration tests should be in accordance with NEMA Stds. MG 1, 7 for standard machines, as necessary to check the operating characteristics of the machine. When there are special requirements, i.e., lower than standard levels of vibration for a machine, NEMA Stds. MG 1, 7 for special machines is recommended. Here we dynamically balanced the rotor using Schenk horizontal balancing machine.

We invested high-end instruments for quality control. Customer satisfactions made us strong, expand, and exist since 1996. Prior to energizing the motor, we conducted off-line testing for the following electrical parameters:

Energize the motor and measure its vibration levels, bearing temperature, speed using Falcon Smart Portable Vibration Analyzer.

Vibration levels should passed the following standard:

Commissioning the motor in the field is very challenging to us. Again, we encourage our Clients to provide us the full history of their motor for further analysis and help them minimize a repetitive breakdown.

High vibrations due to resonance, weak foundations, or misalignment will increase stray load losses. ALPS MSI offers vibration analysis contract and corrective maintenance.

Our instrument for vibration analysis:

Misalignment increase stray load losses, thereby increase power consumption (kW) as shown below:

Our instrument to correct misalignment – Fixturlaser NXA Alignment System.

Another challenge is to measure the actual power drawn after repair and compare to previous data (if available from the client before hand).

DC Motor Repair

ALPS MSI had gained the expertise in the repair or rewind of DC MOTOR. We outsource our raw materials in Australia or USA.

Reasons why DC Motor Fails:

DC Motors – Reasons for Failure

Three common causes of DC Motor Failure include:

  • Carbon Brush wear
  • Carbon Dust
  • Commutator Surface wear
  • Bearings

We can repair and overhaul or carry out full repair, rewind or overhaul of all types and sizes of DC Motors. With the latest DC Motor Repair equipment and full knowledge of the DC Motor Market we are able to offer the solution you need to keep your motors up and running.

DC MOTOR FIG 1
DC MOTOR FIG 2