Frequently asked questions

Yes. The LED Drivers class, typically 10–200 W, covers constant-current drivers for LED modules, commonly 0.35–3.5 A, and constant-voltage drivers at 12, 24 or 48 V DC for LED strips and linear modules.

Power supplies for OEM products, including combined CC+CV outputs, are part of the CC/CV & Custom Power Supplies class. The comparison of constant-current and constant-voltage drivers explains which suits which load. Where an installation has both kinds of load, each type is used on its own circuit.

A servo controller is the control board inside a servo voltage stabilizer. It measures the output voltage, compares it with the set value and drives the servo motor to raise or lower the voltage. Adjustments for set point, sensitivity and time delay are usually made with on-board trimmers.

Invitrona's servo controllers are single-phase and three-phase cards for mounting inside a host enclosure, intended for stabilizers up to 500 kVA. Sensing range, motor drive and terminal assignment are confirmed against the host design.

A servo voltage stabilizer holds its output voltage close to a set value while the incoming supply varies. A control circuit measures the output and drives a small servo motor that adjusts a variable transformer; a buck-boost transformer in series with the load then adds or subtracts voltage.

Correction is continuous, so output can be held within a narrow band, typically ±1% within the stated input window. Because correction is mechanical, it proceeds at a limited rate, typically 6–25 V per second, so a large step takes a few seconds. See servo and static voltage stabilizers for how this compares with electronic correction.

Industrial and AC-to-DC rectifiers are typically built from about 50 A to 5,000 A DC and 6 V to 220 V DC, with constant-current or constant-voltage control. Air-cooled and oil-cooled designs are used, depending on rating and environment.

The right rating depends on the process: maximum current, the voltage at that current, the control mode, any ripple limit and the duty cycle. Share those details in the enquiry for a proposal.

Servo voltage stabilizers and the other kVA-rated voltage-regulation products are offered in single-phase and three-phase formats up to 500 kVA. Single-phase servo units are typically up to 25 kVA; larger ratings are three phase.

The rating for a particular installation is not chosen from a list. It follows from the connected and operating load, the largest motor start and the recorded incoming voltage. Share that information through the enquiry form and the rating is proposed at engineering review.

The transformer class listed on this site covers three-phase, oil-immersed transformers with ONAN cooling, typically 25–2,500 kVA. The usual arrangement is 11 kV to 433 V with a Dyn11 vector group; 22 kV and 33 kV classes are by assessment.

Rating, voltages, vector group, tappings, losses and the installation arrangement are agreed for each project. If your specification calls for a different construction or cooling method, state it in the enquiry so it can be reviewed.

Match the stabilizer to the supply and the load. A site with a single-phase supply, or a single-phase load fed separately, uses a single-phase unit. A site with a three-phase supply normally uses a three-phase stabilizer.

Where a three-phase supply feeds mostly single-phase loads, the phases are often unevenly loaded. A three-phase stabilizer with independent phase control corrects each phase separately. The single-phase and three-phase comparison sets out the differences.

Sizing starts from the load, not the building. The inputs are the connected and peak operating load in kVA (kW divided by power factor), the largest motor start, and the recorded incoming voltage on each phase.

A margin, typically 20–25% above the peak operating load, is added once. The stabilizer's input window must also cover the lowest recorded voltage, because input current rises as input voltage falls. The article on sizing for a multi-site rollout works through an example.

It depends on how the supply varies and how the load reacts. Servo stabilizers suit supplies that drift slowly over a wide range and are well established at larger ratings. Static tap-changing designs, switched by relays or thyristors, correct in steps and typically hold the output within ±2–5%; they suit dedicated loads and smaller supplies, typically up to about 100 kVA, that tolerate a few per cent of variation.

A voltage record and the load list usually make the choice clear. See servo and static stabilizers compared for the criteria side by side.

Share the process type, the maximum DC current and the voltage needed at that current, the normal operating point and the control mode (constant current, constant voltage or a programmed ramp). Add any ripple limit set by the process, the duty cycle and the installation environment, including fumes and ambient temperature.

The distance between rectifier and tank or cell also matters, because DC connections at high current lose voltage. The article on selecting a rectifier for plating and electrolysis explains each input.

Start with the electrical requirement: input range, output type (constant current or constant voltage), output values, power and any dimming or control interface. Then the mechanical and thermal requirement: space, mounting, connectors, maximum ambient at the supply and ingress protection.

Add the target market and applicable standards, expected volumes and the validation plan. Missing items can be marked as open. The OEM power solutions page describes how a design-in requirement is reviewed.

Record the voltage on each phase, phase to neutral and phase to phase, over at least a week that includes peak and off-peak hours. Note the minimum and maximum, how quickly the voltage moves, and any dips when large motors start.

A logging instrument gives a far better basis than spot readings taken during a site visit. Add a note of the equipment that trips or fails, and when. If a recording is not available, say so in the enquiry; an engineer can advise on what to measure.

It depends on the product. Standard voltage stabilizer and rectifier enclosures are for indoor use. Oil-immersed transformers are commonly installed outdoors in a yard or substation. Sealed LED drivers are made for outdoor and damp luminaires, within their stated ingress protection and temperature limits.

Outdoor placement of equipment designed for indoor use needs a separately reviewed enclosure and environmental specification. State the location, ambient range and exposure in the enquiry.

A bypass lets the site isolate the stabilizer for maintenance or a fault while the load is fed directly from the supply. Without one, maintenance means switching the load off.

Whether a bypass is needed, and whether it is manual or automatic, depends on how critical the load is and the site's operating procedures. When the load runs on bypass it receives the unregulated supply, so the procedure should say which equipment may run in that condition. The bypass arrangement is defined in the technical scope.

An oil-immersed transformer needs a foundation or plinth designed for its mass, a delivery and lifting route, safe clearances, ventilation for its losses and oil containment where the regulations or the site require it. Earthing, cable or busbar terminations and protection on both sides are planned at the same time.

The customer and Invitrona agree in the technical scope who prepares each item. Share the site layout and the applicable utility and project requirements in the enquiry.

Standard stabilizer enclosures are for indoor installation in a dry, ventilated location, on a level floor or plinth, close to the distribution board they feed. Leave clear space around the unit for cooling air and for maintenance access, and keep it away from water, dust and direct heat sources.

Plan cable entry and the bypass arrangement before delivery. If the only available location is outdoors, hot or dusty, state that in the enquiry so the enclosure and cooling can be reviewed.

Use the service request form. Describe the equipment, its location, what has been observed and when it started. A photograph of the nameplate helps identify the unit and its records.

If the equipment is behaving unsafely, isolate it according to the site's approved procedure before anything else. The service request is reviewed and the next step is agreed with you; the support arrangement for your equipment is as stated in its quotation or service agreement.

A servo stabilizer has wearing parts: the brush or roller contact on the variable transformer, the servo motor and its drive. These are inspected periodically and replaced when worn. Routine checks also cover cooling fans and air paths, oil level and condition on oil-cooled units, tightness of terminals, indication and the bypass arrangement.

The interval depends on the duty, the environment and how often the unit corrects. The maintenance schedule for a supplied unit is given in its operating documentation. Maintenance on live equipment is carried out only by trained persons following the site's safety procedure.

Include the product class and rating, the serial number from the nameplate, the site location and how the equipment is used. Describe the symptoms: alarms or indications shown, input and output readings if they can be taken safely, and when the problem occurs.

Note any recent changes, such as new loads, supply work or relocation. Photographs of the nameplate, the display and the installation help. Separate what has been observed from what is suspected; diagnosis follows from the facts.

Invitrona is based in New Delhi. Supply and service across India are by assessment: the location, equipment type and support needed are reviewed for each requirement, and the arrangement is stated in the proposal.

Include the site locations in your enquiry, especially for a multi-site programme, so the support arrangement can be considered from the start rather than after the equipment is chosen.

Use the enquiry form to describe your requirement: the product class, the application, the load or duty, the supply conditions and the installation location. Attach or describe any specification you are working to.

The requirement is reviewed by engineering. Where information is missing, you are asked for it before a configuration is proposed. The quotation then states the configuration, scope of supply, exclusions, documentation and commercial terms, so you can compare complete scope rather than price alone.

The documents depend on the product and the agreed scope. They typically include the technical specification of the supplied configuration, drawings where applicable, operating and maintenance information, and inspection or test records when included in scope.

If your project needs particular documents, such as a factory acceptance test, specific drawings or a documentation format, list them in the enquiry so they are included in the quotation.

The scope of supply is stated in each quotation. It lists the equipment and its configuration, included accessories and protection, documentation, inspection and testing, packing and any installation or commissioning support.

Equally important is what is excluded: civil work, cabling, site preparation, permits or utility approvals, for example. Responsibilities on each side are written down so that nothing is assumed. If a quotation leaves an item unclear, ask before ordering.

Warranty terms are stated in the quotation. They depend on the product, its configuration and the scope of supply, including whether installation and commissioning are part of it.

Read the warranty terms with the operating and maintenance conditions they assume, and keep the commissioning record and maintenance log; these are usually needed to support a warranty claim. Questions about the terms can be raised before the order is placed.

Most of this equipment is configured for its duty: rating, voltages, phase arrangement, protection and enclosure follow from the application. The website therefore describes each product class with typical ranges and the information needed to specify it.

The exact configuration, with its ratings and conditions, is defined in the proposal for your requirement. Datasheets on this site are named by product class and rating band.

Use the enquiry form for a new requirement and the service request form for installed equipment. Both forms ask for the details an engineer needs, so the first reply can address the requirement itself. The website does not list a telephone number or email address.

Postal correspondence can be sent to INVITRONA ELECTRICALS LIMITED, A-56, Naraina Industrial Area, Phase 1, New Delhi 110028, India.

INVITRONA ELECTRICALS LIMITED was incorporated on 25 May 1992 in New Delhi, as a public company limited by shares, with corporate identity number U47590DL1992PLC048891.

The company engineers and manufactures electrical power equipment in four families: voltage regulation and power quality, transformers and power distribution, rectification and DC power systems, and power supplies and LED drivers. See the products section for each family and its product classes.

INVITRONA ELECTRICALS LIMITED is based at A-56, Naraina Industrial Area, Phase 1, New Delhi 110028, India. The office, works and registered office are at the same address. The website lists no other branch or office.

Supply and service across India are by assessment. To discuss a requirement, use the enquiry form; for installed equipment, use the service request form. Postal correspondence goes to the same address.