From the works
Company updates and short guides for people who buy LT panels.
Shivanagar becomes our main works
All operations now run from Shivanagar.
What IEC 61439 compliance means when you buy an LT panel
What to ask your panel builder to show you.
Power factor correction: when you need detuned reactors
Harmonics and capacitor life.
How to prepare an SLD and BOQ for an accurate quote
The inputs we need.
PCC vs MCC panels: which one does your plant need?
Where each one fits in a plant.
How to size an APFC panel for your plant
kVAr, steps and harmonics.
DG synchronisation panels explained
How parallel generators share load.
Thyristorised capacitor panels and 7% detuned reactor panels
Fast switching and harmonic-safe capacitors.
Latest trends in power factor control and harmonic compensation
What is changing in PF correction.
Form of separation in LT panels: Form 1 to Form 4b
How much isolation inside the panel.
Busbar sizing and short-circuit rating for LT panels
Current, fault level and temperature rise.
ACB or MCCB: choosing the incomer for your panel
Where each breaker fits.
IP rating and enclosure: indoor, outdoor and dusty sites
Choosing protection for the site.
VFD panel or soft starter: which one for your motor?
Control options for motors.
Shivanagar becomes our main works
Shivanagar, Patancheru is now the main plant and office for all Omega Power Controls operations. Enquiries, drawings and dispatch continue to reach us on the same phone numbers and email.
What IEC 61439 compliance means when you buy an LT panel
IEC 61439 covers low-voltage switchgear and controlgear assemblies. Compliance rests on two things: the design of the assembly is verified, and every assembly built from it is checked by routine verification before dispatch.
When you buy a panel, ask the builder for the design verification record for that assembly type, the routine test record for your panel, and the approved GA and SLD drawings. Ratings that matter to you are the short-circuit rating, the busbar current rating, the form of separation and the degree of protection. They should be written into the offer, not assumed.
Power factor correction: when you need detuned reactors
A plain capacitor bank corrects power factor, but where the load produces harmonics, capacitors can overheat or resonate with the supply.
Plants with drives, UPS systems or other non-linear loads usually need detuned reactors in series with the capacitors. Fast-changing loads may need RTPFC, which switches without the delay of a contactor. Share the load list and, if you have it, a harmonic measurement, and we size the bank around it.
How to prepare an SLD and BOQ for an accurate quote
The more of the following you send, the fewer questions we need to ask before pricing.
Incomer rating and type, fault level, busbar material and rating, the outgoing feeder schedule, protection and metering requirements, form of separation, degree of protection, preferred component makes, and the site conditions. If you only have a rough single-line diagram, send that: we come back with questions and an indicative scope.
PCC vs MCC panels: which one does your plant need?
A PCC (Power Control Centre) distributes bulk power from the transformer or generator, while an MCC (Motor Control Centre) starts, protects and controls individual motors. Most industrial plants need both: a PCC upstream feeding several MCCs downstream.
PCC. Built around incoming breakers (ACB/MCCB) and large outgoing feeders, usually from about 400 A up to several thousand amps. It handles the main load, bus-coupler and changeover duties, and is designed for high fault levels.
MCC. Built from plug-in or fixed withdrawable feeder modules with starters (DOL, star-delta, soft starter or VFD), overload relays and motor protection. Each motor gets its own compartment, so one motor can be serviced without shutting the whole line.
How to choose. Pick a PCC when the job is incoming supply, large feeders or main distribution. Pick an MCC when you have many motors (pumps, fans, compressors, conveyors) that need starters, interlocks and individual isolation. For a typical factory the answer is a PCC feeding one or more MCCs.
What to tell us for a quote. Incoming supply and fault level, list of feeders or motors with ratings, starter type, form of separation required, IP rating and any ABB or other make preference. Send it through the enquiry form and our team will reply within one working day.
How to size an APFC panel for your plant
An APFC (Automatic Power Factor Correction) panel is sized from your load in kW, your present power factor and the power factor you want to reach, usually 0.95 to 0.99.
The formula. kVAr = kW × (tan φ1 − tan φ2). Example: a 500 kW load at 0.80 power factor, corrected to 0.98, needs about 500 × (0.75 − 0.20) = 275 kVAr, so a 300 kVAr panel is a sensible choice.
Steps and stages. Split the total into stages (for example 12 steps of 25 kVAr) so the controller can follow load changes smoothly. Smaller steps give finer control but cost more.
Harmonics matter. If your plant has VFDs, UPS or other non-linear loads, plain capacitors can resonate and fail early. Detuned reactors (typically 5.67%, 7% or 14%) or harmonic filters are needed. A harmonic study or a simple power-quality log tells you which.
Capacitor type. Heavy-duty or APP capacitors are preferred for industrial use, with contactors rated for capacitor duty.
What to share with us. Last 3 electricity bills (kVA demand and power factor), transformer rating, list of VFDs and large motors, and any harmonic readings. Our team will size the panel and send a quotation.
DG synchronisation panels explained
A DG synchronisation panel lets two or more diesel generators run in parallel, share the load equally, and feed one common bus. You get more capacity, redundancy and better fuel use than a single large set.
What is inside. Generator incoming breakers, a synchronising controller (auto-sync, check-sync and load-sharing), protection relays (reverse power, over/under voltage and frequency, overcurrent), busbars and a changeover to the mains. Many panels also include a PLC and a touchscreen for monitoring.
How it works. The controller matches voltage, frequency and phase angle of the incoming set with the running bus, closes the breaker only inside the safe window, then shares kW and kVAr in proportion to each set's rating. Sets can be started or stopped automatically as the load rises or falls.
When you need one. Data centres, hospitals, large factories and commercial buildings where a single failure should not stop operations, or where load grows in phases and you want to add sets later.
What to tell us. Number and kVA of generators, make of engine and alternator, mains parallel requirement (yes or no), load-shedding needs and the site layout. We will propose the panel and send a quote.
Thyristorised capacitor panels and 7% detuned reactor panels
Two upgrades make a power factor panel suit modern plants: thyristor switching for loads that change in milliseconds, and detuned reactors for plants with harmonics. Many industrial panels need both.
Thyristorised (TSC) panels. Instead of contactors, thyristor switches connect each capacitor step at the right instant, when the voltage across it is nearly zero. Switching takes less than a cycle, there is no contact wear and no switching surge. They suit rapidly changing loads such as welding machines, presses, cranes, lifts, injection moulding and DG-fed plants, where a contactor panel reacts too slowly and the power factor swings.
Why not just use contactors everywhere. Contactor panels (APFC) respond in seconds and are the economical choice for steady loads. TSC panels cost more because of the thyristor modules, heat management and faster controller, so we recommend them only where the load really changes quickly.
7% detuned reactor panels. A reactor connected in series with each capacitor shifts the resonance of the circuit below the dominant harmonic. With a 7% reactor the tuning frequency is about 189 Hz on a 50 Hz system, below the 5th harmonic (250 Hz), so the 5th and higher harmonics cannot excite the capacitor into resonance. This is the standard choice when 5th harmonic is the main problem, which is typical with VFDs, UPS and rectifier loads.
When to choose 5.67% or 14%. 5.67% reactors tune near 210 Hz and are used when 3rd harmonic is also present; 14% reactors tune near 134 Hz and are used when 3rd harmonic is strong. The right percentage depends on a harmonic measurement, so we ask for a power-quality log or a list of non-linear loads before quoting.
Rated capacitors. Detuned panels raise the voltage across the capacitor, so the capacitors must be rated for it (for example 440 V or 480 V on a 415 V system) and the reactors rated for the harmonic current they will carry.
Combining both. TSC and detuned reactors can be combined in one panel: thyristor steps for the fast-changing part of the load and contactor steps for the steady part. We size the split from your load profile.
Latest trends in power factor control and harmonic compensation
Power factor correction is moving from simple capacitor banks to monitored, harmonic-aware systems. These are the trends we see on the ground in Indian industry.
More harmonics, so detuned as the default. VFDs, LED lighting, UPS systems, EV chargers and solar inverters add non-linear load in almost every plant. Plain capacitor banks are now the exception; detuned reactor panels are the safer default, and harmonic measurement before design is becoming standard.
Active harmonic filters. Active harmonic filters (AHF) measure the harmonic current and inject an opposite current to cancel it. They respond across a wide range of harmonics and can also correct reactive power. They cost more than passive reactors, so they are used where harmonics are high, load varies widely or limits such as IEEE 519 must be met at the supply point.
Real-time and hybrid correction. Thyristor-based real-time panels, and hybrid systems that pair a passive detuned bank with a smaller active unit, give fast response with lower cost than a fully active solution.
Smart controllers and monitoring. Modern PF controllers log power factor, harmonic distortion, capacitor current and temperature, raise alarms for failing capacitors and connect over Modbus or Ethernet to a SCADA or energy system. Remote monitoring means a weak capacitor is replaced before it fails.
Billing and regulation. Utilities in India reward a high average power factor and penalise a low one, and many now bill on kVAh, so a well-corrected power factor reduces the bill directly. Check your own tariff conditions for the exact limits.
Reactive power from renewables. Plants with rooftop or captive solar often see their grid power factor change during the day. Automatic correction that tracks the grid-side meter keeps the power factor steady as solar output rises and falls.
Our approach. We start from your electricity bills and, where possible, a power-quality log, then recommend the simplest panel that does the job: APFC, detuned APFC, thyristorised, or a hybrid with active filtering. Send your details through the enquiry form.
Form of separation in LT panels: Form 1 to Form 4b
Form of separation describes how busbars, functional units and terminals are separated inside a panel (IEC 61439-2). A higher form protects people working on one unit while the rest stays live, and limits the spread of a fault, but it costs more and needs more space.
Form 1. No internal separation. The cheapest option, used for simple distribution boards.
Form 2. Busbars are separated from the functional units (2a without, 2b with separated terminals for external conductors).
Form 3. Busbars and units are separated, and the units are also separated from each other (3a and 3b by terminal arrangement).
Form 4. Units are separated from each other and the terminals for outgoing cables sit in their own compartment (4a same compartment as unit, 4b separate compartment). Form 4b is common for MCC panels where a motor feeder must be serviced while others run.
How to choose. Ask what must stay running during maintenance, who will work on the panel and the cost of an unplanned shutdown. Process plants, data centres and hospitals usually choose Form 3b or 4b; simple building distribution often uses Form 2b.
What to put in your enquiry. Required form, incoming current, short-circuit rating, IP rating and whether feeders should be withdrawable.
Busbar sizing and short-circuit rating for LT panels
A busbar must carry the rated current without overheating and survive the highest fault current the supply can deliver. Both numbers decide the busbar size, support spacing and the type of breakers.
Rated current. Choose the busbar from the panel rating (for example 800 A, 1250 A, 2500 A) and the ambient temperature. Copper and aluminium differ in current-carrying capacity per square millimetre, so the cross-section differs. Temperature rise limits are checked against IEC 61439.
Short-circuit rating. Panels are rated for a short-time withstand current (Icw, for example 50 kA for 1 second) and a peak current. The rating must be equal to or higher than the prospective fault level at the panel location. Your transformer rating and impedance give a first estimate.
Why support spacing matters. During a fault the electromagnetic force on busbars is very high. Closer insulated supports, thicker bars and proper bracing keep them from bending or breaking.
Derating. Enclosure ventilation, IP rating, high ambient temperature and a tightly packed panel reduce the usable current. A good design accounts for this instead of relying on nameplate figures alone.
What we need from you. Transformer kVA and impedance (or fault level at the site), required current rating, copper or aluminium preference and ambient temperature.
ACB or MCCB: choosing the incomer for your panel
Both breakers protect against overload and short circuit, but they suit different current ranges and duties. The right choice affects cost, space and how the panel can be maintained.
MCCB (moulded case circuit breaker). Compact and economical, commonly used up to about 1600 A. Good for feeders and for incomers of small and medium panels. Many have adjustable electronic trip units with metering options.
ACB (air circuit breaker). Used for higher ratings and heavy duty, typically 800 A and above. Withdrawable ACBs can be isolated and serviced without shutting the whole panel, they offer high short-circuit withstand and wide trip-setting flexibility, and they support selective coordination (upstream and downstream devices trip in the right order).
How to choose. Look at incoming current, fault level, need for selectivity, space available and how often the breaker may need maintenance. Large plants usually use an ACB incomer with MCCB feeders.
Protection settings. Whichever you pick, correct settings matter: overload, short-time, instantaneous and earth fault. We include a basic coordination check with the quotation where details are available.
As an ABB Channel Partner. We supply ABB breakers and other leading makes, selected to your specification and budget.
IP rating and enclosure: indoor, outdoor and dusty sites
The IP code tells you how well an enclosure keeps out solids and water. Choosing too low a rating risks failures; too high adds cost and heat.
Reading the code. IP54 means dust-protected and protected against splashing water. IP65 means dust-tight and protected against water jets. IP42 is common for clean indoor electrical rooms.
Indoor electrical room. IP42 or IP54 is usually enough. Ventilation louvres with filters help heat escape.
Outdoor or washdown. Use IP65 or better, a canopy against sun and rain, and attention to condensation and heating.
Dusty or corrosive plants. Cement, textile, chemical and coastal sites need a higher IP rating and a suitable paint or powder-coat specification. Door gaskets and cable-gland sealing matter as much as the enclosure.
Heat and ventilation. A sealed enclosure holds heat. Thermal calculations, fans or air conditioning may be needed, and the current rating may need derating.
Finish and thickness. Sheet thickness, pre-treatment (such as seven-tank phosphating) and powder-coat quality decide how long the panel lasts. Tell us your site conditions and we will specify accordingly.
VFD panel or soft starter: which one for your motor?
Both reduce the stress of starting a motor, but they do different jobs. A VFD controls speed continuously; a soft starter only ramps the motor up and down.
DOL and star-delta. Direct-on-line is simple and cheap but draws a high starting current. Star-delta reduces it for medium motors but gives a jerk on changeover.
Soft starter. Ramps voltage up smoothly, limiting starting current and mechanical shock. Good for pumps, fans and conveyors that run at fixed speed. A bypass contactor reduces heat after ramp-up.
VFD (variable frequency drive). Changes the speed to match demand, which can cut energy use sharply on fans and pumps because power falls with the cube of speed. It also gives precise control, torque at low speed and gentle starts.
Points to plan for. VFDs create harmonics, so input reactors or filters may be needed. Long motor cables may need output reactors. The panel must be ventilated for the heat the drives release.
Choosing. If the motor runs at a fixed speed, a soft starter is often enough. If flow, pressure or speed must vary, a VFD usually pays back through energy savings. Share motor kW, load type and duty and we will recommend.