FAQ

Existing motors running in the industries which are more than 10 years old, rewound multiple times, having efficiencies lower than IE2 class as per IS 12615 should be considered for replacement.

Under the current EESL program, 3-Phase squirrel cage induction motors suitable for safe area operation (i.e. Non-flameproof type) and adhering to only Premium Efficiency class IE3/ Super Premium Efficiency class IE4 as per IS 12615: 2018/ IEC 60034-30-1 shall be supplied to the End Users. These motors are suitable for continuous operation (S1 duty) applications.

To participate, the users can logon to specially designed EESL Web Portal (www…………………………………) for sending their inquiry and other details.

This is a voluntary program launched by EESL for the benefit of industries. There is no fee being charged for participating in NMRP.

The type & range of IE3 motors covered are mentioned below-

Industries participating in NMRP shall be able to avail following benefits from the program-

• Lower purchase price of motors compared to the retail market price
• Easy repayment option through Quarterly installments
• High-Quality Motors of reputed brands
• 3 years of comprehensive warranty
• Other value addition support

Apart from Motor cost, EESL will charge a Project Management Consultancy (PMC) fee (one time).

EESL shall be supplying motors manufactured in India.

Motors to be supplied within 8 weeks (for IE3 motors)/16 weeks (for IE4 motors) from the date of the client’s formal purchase order to EESL.

The minimum quantity of motors as per the EESL program range for procurement in case of upfront mode shall be 10 nos. while for ESCO mode shall be 25nos. or INR 10 lakhs whoever is higher.

To ensure the quality EESL shall be doing a periodic inspection at Motor Manufacturer's premises for the motors which are supplied as per LoA issued to them. All motors will be undergoing routine tests and follow a pre-dispatch inspection by EESL or its empanelled third-party agency (TPA).

All the complaints shall be made to EESL through the complaint tab on the website home page by clicking on……………………………………………………………………

The service engineer shall attend the complaint within 3 complete working days of the complaint getting logged at the customer care centre helpline of EESL or its identified agency(ies).

Full and Conclusive Resolution of Complaints: Within 7 complete working days of complaint getting logged at the customer care centre helpline of EESL or its identified agency(ies), subject to the following restrictions:

• Minor faults are to be resolved within 1 complete working day of attending the complaint.
• Major faults are to be rectified within a maximum of 5 complete working days of attending the complaint.

An option of a walkthrough audit is given by EESL wherein an agency empaneled by EESL shall conduct a walkthrough survey for potential customers on actual cost basis.

All motors supplied, shall be covered under a written warranty for 3 years from the date of receipt of material at the customer site.

Motors under the NMRP scheme can be procured through the following 2 options:-

Mode#1: PMC/Upfront Investment Mode: In this mode, EESL shall limit itself only up to the supply of motors at lower than market price including its Project Management Consultancy (PMC) fee. EESL shall not maintain any inventory and the entire material shall be shipped directly from manufacturer’s production facility/warehouse to customer location. While EESL shall facilitate the entire project monitoring and warranty obligation for its client. For this modality motors shall be supplied on advance payment basis. However, recognising that not all trades can be done on an advance basis, a mechanism of payment after deliveries could be effected under a 100% coverage through irrevocable Letter of Credit (LC)/Bank Guarantee (BG) for payment security which is to be established/submitted by the client to EESL prior to placement of Purchase Order (PO) by EESL to the vendor. The exceptions under this rule would be any Central/State Govt. owned entity procurement from EESL under GEM wherein payment security is guaranteed.

Model#2: ESCO Mode: In this mode, EESL shall not only supply the motors to its client but also provide finance support for procurement of motors. There is no upfront financial implication on the industrial client as EESL will do the entire investment initially along with project monitoring up to a period of 3 years. Client will repay EESL in form of Equated Quarterly Instalments (EQIs) within 3 years. Here, the project cost will be Material cost plus PMC fees plus the Financing cost for timeline mutually agreed by the user and EESL. Further, EESL is ensuring its payment security by taking Payment Security Bank Guarantee (BG) or any suitable mode of payment security (viz. Insurance bond etc) as applicable from the respective Client equivalent to the capital cost of motors (Motor cost including Transportation + EESL PMC + Financing Cost) under this mode. Payment security is to be established/submitted by the client to EESL prior to placement of Purchase Order (PO) by EESL to the vendor.

As under the ESCO mode, the user has the benefit of paying the total project cost in 3 years instead of repaying upfront, EESL shall charge a finance cost over and above the project cost which shall be in line with the market trend or lower.

Freight & insurance charges shall be borne by EESL/EESL’s Supplier till the delivery of motors at the customer site.

End Users purchasing the motors shall have to provide a Bank Guarantee (BG) or Letter of Credit (LC) to EESL.

The responsibility of the installation of new motors shall lie with users solely.

Nearly 60% of all loads are utility loads which are centrifugal loads such as fans, pumps, and compressors. They make a major target for IE3 applications. After choosing major loads, select those with over 12 hours of operation in a day to sustain the gains of IE3 motors. Also, motors with a loading factor or loading percentage greater than 60% should be initially targeted.

It is the same for all motors as all motor manufacturers offer standard IE3 motors for IP55 and 50⁰C ambient, with temperature rise limited to class B level at 90% loading of the rated power. Anything above these, like IP56, 57, 65, etc and >50⁰C, etc need special selection according to its application.

Today leading manufacturers offer HEMs (IE3 & above) with appropriate insulation having dual coat wire and VPI treatment which makes it suitable for use with VFDs. However, if VFDs are improperly installed or used with unsuitable applications, negative side effects may occur when applying them to motors, regardless of the motor’s efficiency. Currently, EESL is offering motors suitable for variable torque applications only.

As IE3/IE4 motors tend to operate with reduced “slip” or at a slightly higher speed than their standard-efficiency counterparts. The Law of Affinity states that the power is directly proportional to the cube of load speed. In contrast, the quantity of airflow or liquid delivered varies linearly with speed. A seemingly minor increase in a motor’s full-load rotational speed from 1,430 to 1,455 RPM i.e. 1.7% can result in a 5% increase in the load that the rotating equipment places on the motor, completely offsetting the energy and cost savings typically expected as a result of purchasing an IE3 motor.

While replacing old, lower efficiency motors for variable torque applications be sure of the following-

• Check for correct sizing of new motors to be installed w.r.t loading
• For a belt pulley arrangement, correction in PCD of the pulleys can be done to match the final speed
• For direct coupling, trimming of an impeller or replace, if required. Similarly for fan/blower
• Used of VFDs to match speed variation can also be done

As motors with higher efficiencies have lower transient reactance than lower efficiency motors, their starting current can spike higher than the full-load current of less efficient motors. This very high starting current may cause the nuisance tripping of Instantaneous Trip Circuit Breakers (ITCB), though no fault or a short circuit has occurred. However, starting current varies widely at each efficiency level. Type 2 coordination is a chart made available by the BIS as well as IEC (IS/IEC 60947-4-1) for control and protection components. If the higher starting current is seen as fault current, the relay may get tripped. Type 2 coordination for IE2, IE3 and IE4 motors are published.

No. Starting torque also referred to as locked rotor torque, is the minimum torque produced by the motor at rated voltage and frequency, at all angular positions of the rotor. On average, starting torque does not vary significantly for motors with different efficiency levels of the same size. When selecting a motor, it is important to specify the needed starting torque because it varies widely across motor sizes and models. This is especially critical when sizing a higher efficiency motor replacement with Eff 1 class of motor.

Power Quality limits shall be the same as it is applicable for currently installed standard motors. A disclaimer is mentioned in IS 12615/1989 for voltage variations which holds true for all efficiency class of motors not limited particularly to IE3/IE4 motors. The excerpt from IS 12615 is given below: - “It may be noted that the efficiency and PF of the motor are affected by the variation in the supply voltage conditions and hence it is felt necessary to emphasize that the supply voltage condition should be stable to obtain the desired effect in the conservation of energy. Otherwise, if the supply voltage conditions are not stable, the improvement in the efficiency of the motor will have only a marginal effect on energy conservation.”

The IE3 motors achieve their efficiency by reducing resistive losses in the motor windings (among other factors). These motors draw a very high inrush current greater than standard motors. For high inertia loads (fan & pumps) with greater than 10 seconds starting duration, class 20 or class 30 relay may be used. The use of microprocessor adjustable relays is recommended rather than thermal relays.

Maintenance practices are same for all motors in general though as a good practice for proper maintenance we should consider proper cable selection, feeder distance, harmonic protection, VFD duty compatibility, high temperature synthetic grease (Unirex N3), use proper mounting and dismounting tools for the bearings and proper alignment of the shafts.

PF values for all Eff. class are mentioned in the manufacturer’s catalogue which has a slight incremental change. To avoid additional PF correction capacitors, we should optimally size the motor ratings such that the PF remains high. PF at partly loaded motors is very low.

The advantages of using variable frequency drives with motors are as below:-

• Good & precise speed control in the required speed range
• Easily adjust the frequency or speed of the motor and keep it fixed under variable system parameters
• Limit the starting current of the motor without affecting the motor torque
• Reduce starting losses
• Reduction in energy consumption for centrifugal loads like pumps, fans, etc. by operating at lower speeds without the need for throttling or use of a damper