Unable to Recharge the prepaid meter

Solution: Connectivity Check: Confirm the meter is successfully communicating with the server. Serial Number Verification (SmartComm): Access the SmartComm Customer Master and ensure the serial number recorded matches the physical serial number of the connected meter. Duplicate Configuration Check: Verify that no two meters are incorrectly configured with the exact same serial number in the system.

Email Configuration SMTP Details Outlook

Solution: SMTP Host/Server Name: For Outlook.com: smtp-mail.outlook.com For Office 365/Microsoft 365: smtp.office365.com SMTP Port:587 (recommended) Encryption Method: STARTTLS Authentication: Your email account needs to be authenticated, so enable login or use the ""My outgoing server (SMTP) requires authentication"" option in your email client. Username: Your full Outlook email address (e.g., yourname@outlook.com or yourname@domain.com) Password: Blank

Email Configuration App Password creation for Gmail account

Reason - Gmail will work only with a secure encrypted app password Solution: Go to your Google Account settings. Navigate to the Security tab. If you don't have it enabled, turn on Two-Step Verification. Find and click on App passwords. Select an app name (like ""SMTP"" or ""Mail Client"") and click Generate. Copy the generated 16-character password and use it in your mail client's password field instead of your main Gmail password.

Email Configuration SMTP Details Gmail

Solution: Gmail SMTP Settings SMTP Server: smtp.gmail.com Port: 587: (requires STARTTLS/TLS) 465: (requires SSL) Authentication: Required Username: Your full Gmail address (e.g., user@gmail.com) Password: An App Password generated from your Google Account security settings Security/Connection: TLS or SSL, depending on the port chosen

Transfer existing sensor to a different gateway

Reason - Loss of old data stored under device id created Solution: To prevent data loss, edit the sensor and use the "Move to Gateway" option to transfer the sensor to a different gateway.

Asset list is not available in the filter

Reason - The asset is not assigned to the organization Solution: Check the asset selection settings in organization settings

Reason - Sensor/gateway limit exceeded Solution: Check license information for sensor/gateway limit

Cannot change the ip address of gateway

Reason - The ip address should is not available Solution: 1. if company network is being used check the accesibility to access 2. check if set ip is with in subnet range 3. Check if Primary and Secondary DNS is correct as per network settings 4. Set the Default Gateway IP to match the router's IP or the company network's default gateway IP.

3rd part meter not communication

Reason - 1. Memory map configuration wrong 2. (10 power -4 )Conversion factor is not available in third party memory map configuration 3. Data on modscan and software is matching but not matching with meter display readings Solution: 1. Verify data via Modscan, check wiring, confirm the meter parameter's datatype/function code in the memory map, and ensure the gateway supports that parameter datatype. 2. Can be added from conversion factor available in Master settings

Could not download certificate

Reason - All mandatory fields are not saved in organisation info settings Solution: All details should be given in mandatory field of organisation settings

Motor Power Factor Compensation

Updated: Sep 08, 2026 | 6 min read

Technical Articles

Published: Jul 14, 2026 by Abhinav L Purkar

Technical Articles

Click on any topic to jump to that section

The various methods of power factor correction are direct compensation, group compensation and centralized compensation. Depending upon the size and the rate of change of loads in an industry, any one or combination of the above methods can be employed. Specifically, in case of agricultural pump-sets and some small scale industries with a few motor loads, the power factor correction can be done by connecting shunt capacitors directly to the motors. This method of compensation is called direct compensation. This is simple and ideal method for reactive power compensation, as this would result in rating optimization of all the upstream switchgear and cables, which reduces overall system losses.

Direct motor compensation can be done in two methods and this article briefs the configuration and selection of the same.

Method - 1

As shown in the figure, the capacitor is connected directly to the motor terminals, after the starter. The capacitors would start supplying reactive power, as soon as the motor is switched ON. This method of compensation can be used for motors with Direct on-line starters. Usually the kVAr rating for a particular motor is given by the respective motor manufacturers, as the kVAr ratings are motor specific. If the motor manufacturer's data are not available, the below given chart can be referred as a ready reckoner, where M kVAr can be selected for various motor ratings (in HP) and motor rpm:

Even though this is the effective method of power factor compensation, there is a limitation in sizing of the capacitors. That is, the maximum kVAr should be decided such that, the rated capacitor current is less than 90% of the motor's no-load current. If this condition is not met, self-excitation may occur, in which the motor acts as a generator. This happens when a motor has enough inertia to keep rotating even after disconnected from the power system and the capacitor is large enough to supply the reactive power needs of the motor. Self-excitation would result in high voltage available at the terminals of the motor and this can damage the contactor and the capacitor. As this method has the limitation in the sizing of maximum kVAr rating, it is not possible to achieve unity power factor.

MOTOR (hp)	3000 rpm	1500 rpm	1000 rpm	750 rpm	500 rpm
2.5	1	1	1.5	2	2.5
5	2	2	2.5	3.5	4
7.5	2.5	3	3.5	4.5	5.5
10	3	4	5.5	5	6.5
15	4	5	6	7.5	9
20	5	6	7	9	12
25	6	7	9	10.5	14.5
30	7	8	10	12	17
40	9	10	13	15	21
50	11	12.5	16	18	25
60	13	14.5	18	20	28
70	15	16.5	20	22	31
80	17	19	22	24	34
90	19	21	24	26	37
100	21	23	26	28	40
110	23	25	28	30	43
120	25	27	30	32	46
130	27	29	32	34	49
140	29	31	34	36	52
145	30	32	35	37	54
150	31	33	36	38	52
155	32	34	37	39	56
160	33	35	38	40	57
165	34	36	39	41	59
170	35	37	40	42	60
175	36	38	41	43	61
180	37	39	42	44	62
185	38	40	43	45	63
190	38	43	45	45	65
200	40	42	45	47	67
250	45	50	55	60	70

MOTOR (hp)	3000 rpm	1500 rpm	1000 rpm	750 rpm	500 rpm
2.5	1	1	1.5	2	2.5
5	2	2	2.5	3.5	4
7.5	2.5	3	3.5	4.5	5.5
10	3	4	5.5	5	6.5
15	4	5	6	7.5	9
20	5	6	7	9	12
25	6	7	9	10.5	14.5
30	7	8	10	12	17
40	9	10	13	15	21
50	11	12.5	16	18	25
60	13	14.5	18	20	28
70	15	16.5	20	22	31
80	17	19	22	24	34
90	19	21	24	26	37
100	21	23	26	28	40
110	23	25	28	30	43
120	25	27	30	32	46
130	27	29	32	34	49
140	29	31	34	36	52
145	30	32	35	37	54
150	31	33	36	38	52
155	32	34	37	39	56
160	33	35	38	40	57
165	34	36	39	41	59
170	35	37	40	42	60
175	36	38	41	43	61
180	37	39	42	44	62
185	38	40	43	45	63
190	38	43	45	45	65
200	40	42	45	47	67
250	45	50	55	60	70

Method - 2

In this method, the capacitor is connected to the motor before the starter and it is switched through a separate capacitor-duty contactor. As the capacitors are disconnected as soon as the motor is switched off, self- excitation is avoided. Hence, there is no need of any limitations in capacitor sizing and unity power factor can be achieved by this method.

The capacitor size (in kVAr) can be calculated by the below formula:

kVAr = kW (tan Φ 1 - tan Φ 2)

Where Φ1 2 = cos-1 (Initial PF) & Φ2 = cos-1 (Target PF)

The limitations are the manual switching of the capacitors and the extra cost incurred for the contactors. Moreover, when the number of motors increase in future, managing all at a time would be difficult.

Motors with Star-Delta Starter:

Specifically for motor with star-delta starter, it is recommended to use method-2. If capacitors are directly connected to the terminals of the motor, the life of the capacitor drops drastically because of the voltage spikes that happen during every star to delta transition. So it will be safer to connect the capacitor before the star-delta starter, as shown in the above figure.

Points to remember:

The operating power factor varies with respect to the percentage loading of the motors. Hence with the varying load, the fixed capacitors would not be able to maintain the unity power factor continuously.
After switching off the capacitor, it is very important to maintain a minimum time delay of 30 to 60 seconds, for switching ON the capacitor again. Else, there are more chances of contactor damage because of charged capacitor.
If the motor is operated with any drives/converters, it is recommended to detune the capacitors by adding series reactors.
It is recommended to use capacitor duty contactors for minimizing the inrush current and hence to maximize the life of contactors and the capacitors

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About the Author

Abhinav L Purkar,

Manager Product Management & Marketing (PMM)

Abhinav Purkar is a Product Management, Marketing, and Application Engineering professional with over 10 years of experience in the Power Quality domain. He has extensive expertise in power quality analysis, harmonic mitigation, reactive power compensation, energy efficiency, and electrical system optimization, helping customers improve system reliability and operational performance. With proven experience in product lifecycle management, market development, portfolio growth, and go-to-market strategy, Abhinav has successfully driven initiatives that enhance customer value and strengthen market presence. His strong technical foundation, combined with strategic business acumen, enables him to bridge the gap between customer requirements and innovative product offerings.