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Knowledge Base

The questions we get asked every week

Most of these come up on the first phone call, and most have a straight answer that nobody bothers to write down. So we wrote them down. No sales copy — if the honest answer is that you do not need the thing we sell, that is what it says.

Topics Covered
ANSWERS
PLAIN ANSWERS no sales copy MCC vs PCC? What does APFC save? Air or water leak test? Do I need a VFD? Is retrofit worth it? Net metering? 30+ QUESTIONS ANSWERED panels · testing machines · SPM · CNC retrofit · solar if you do not need it, we say so
PanelsMCC · PCC · APFC · VFD
MachinesLeak · press · drilling
SolarCost · net metering
Control panels

Panel questions

What is the difference between an MCC and a PCC panel?

A PCC — power control centre sits at the incoming end and distributes power. It takes the supply from the transformer or the main breaker and feeds outgoing circuits, so it is built around busbars sized for the full incoming current and breakers for each outgoing feeder. An MCC — motor control centre sits downstream and starts and protects motors, so it is built around starter feeders in modules, each with its own contactor, overload and isolation.

The short version: PCC distributes power, MCC controls motors. A plant usually has one PCC and several MCCs. PCC panels → · MCC panels →

What does an APFC panel actually save me?

Inductive loads — motors, welding sets, induction furnaces — draw reactive power that does no useful work but is still carried by the supply. That drags your power factor down, and DISCOMs penalise a poor power factor and often reward a good one. An APFC panel switches capacitor banks in and out automatically to keep the power factor near unity.

The saving shows up in two places: the penalty disappears, and your demand in kVA falls for the same kW of useful work, which reduces demand charges. Whether it is worth it depends on your current power factor and your tariff — send us a recent bill and we will do the arithmetic before you commit. APFC panels →

Do I actually need a VFD?

If the load varies, almost certainly. For pumps and fans, power follows roughly the cube of speed — running at 80% speed uses close to half the power. Most fans and pumps are sized for a peak that happens rarely and then run at full speed permanently because a direct starter has no other setting.

If the load is constant and the motor runs flat out all day, a VFD saves nothing on energy, though it still gives soft starting and better control. Honest answer: for a constant-load conveyor, probably not. For an AHU fan or a pump on varying demand, yes. VFD panels →

Why does my panel need ferruled wiring? It costs more.

Because in five years somebody will open it with a fault, and every wire will look the same. Ferrules mean any core can be traced to the drawing in seconds instead of being buzzed out one at a time. The extra cost is small and the payback comes the first time the panel is worked on.

What is a DG synchronizing panel for?

It lets two or more diesel generators run in parallel, sharing load, and lets them come on and off without a break in supply. Without synchronising, transferring load means a gap. For plants where a gap is expensive — process lines, hospitals, data rooms — that gap is exactly what you are paying to avoid. DG synchronizing panels →

Testing machines

Leak and flow testing questions

Air leak testing or water submersion — which should we use?

Air pressure decay gives a number you can log and defend, and it is faster and dry. Water submersion gives a visual verdict people trust and shows you where the leak is, which is what your process engineer needs to stop it happening again.

Many lines end up with both: air screens every part quickly, and only the failures go to water so the leak can be located. Compare leak testing methods →

Why do our plastic parts fail on a leak tester when they are fine?

Because they are expanding, not leaking. Pressure decay assumes the internal volume stays constant. A plastic or composite part grows under pressure, the volume increases and pressure falls — which the machine reads as a leak. The fix is a longer settle time before measurement, lower test pressure, gentler clamping, and often differential testing against a master of the same material. Testing flexible components →

What is the difference between pressure decay and differential testing?

Pressure decay watches the absolute pressure inside your part and looks for it falling. Differential compares your part against a sealed master of similar volume and measures only the difference, which cancels out temperature drift. Decay suits ordinary limits; differential is what you need when the reject limit is tight or the parts are still warm from machining. Air leak testing →

Why can we not leak test hydraulic parts with air?

Safety. Compressed air at high pressure stores enormous energy and a part that bursts becomes shrapnel. Liquid is nearly incompressible, so the same failure releases almost nothing — the part splits and pressure collapses. That is why pressure codes specify liquid, and why our high-pressure rigs use oil or water behind an enclosure. Hydraulic leak testing →

Our silencer passes leak test but the customer rejects it. Why?

Because sealing is not the acceptance criterion — restriction is. A silencer with a blocked or misplaced baffle is perfectly sealed and completely wrong. That needs a flow test measuring back pressure at a given flow, with an upper and a lower limit, because too free-flowing usually means the internals are missing. Air flow testing →

Special purpose machines

SPM and automation questions

What exactly is an SPM?

A special purpose machine is built for one job on one component, rather than being a general-purpose machine set up for a task. You need one when no catalogue machine does exactly what your part requires, or when the cycle time and repeatability you need cannot be achieved by an operator with standard equipment. SPM overview →

What does force-displacement monitoring on a press catch?

Missing washers and components, cross-threaded or off-square bolts, cracked or soft parts, wrong variants, short-fed assemblies and worn tooling. None of these necessarily breaks a force limit or a position limit, but all of them change the shape of the curve — and the machine judges the shape against an envelope learned from your own good parts. Press monitoring with SCADA →

How does a machine know a tap or a drill has broken?

The load or torque signature changes instantly. A broken tool takes almost no torque; a blunt one takes too much. Either way the cycle aborts within a revolution and the part is flagged, so a component with a half-cut thread never reaches assembly. Tapping machines →

At what volume does automation pay for itself?

It is rarely volume alone. The number that usually decides it is what one escaped defect costs you at the customer end, including recall risk — not the labour saving. Tell us your parts per hour, your operator cost and your escape cost, and the answer is usually obvious within a few minutes. Automated testing SPM →

Which PLC brand should we standardise on?

Whichever your maintenance team already knows and your spares cupboard already stocks. A technically superior controller that nobody on site can service is worse than an ordinary one they can. Where there is no existing standard, we recommend based on the application and local support. PLC and SCADA →

CNC retrofit

Machine tool questions

Is our old CNC machine worth retrofitting?

The castings and the ways decide it. If the bed is sound and way wear is within reclaimable limits, retrofitting almost always beats buying new — a fraction of the cost, delivered in weeks, on a machine your operators already know. If it has been badly crashed, run dry for years or has a cracked casting, it is not a candidate and we will tell you so. CNC retrofitting →

Can you just change the controller and leave the mechanics?

You can, and it produces a machine with a nice new screen and the same old accuracy problem. Backlash and way wear are not things a servo can correct if the feedback cannot see them. We survey both sides and quote both, and if only the electronics need doing we say that too.

Solar

Solar questions

Why will nobody give me a price per kW on the phone?

Because the panels and inverter — the standardised part everyone compares — are not what varies. The structure, the roof type, the cable run and the interconnection do, and none of it can be assessed without a site visit. A firm number on a first call is a number that gets revised later. What drives solar cost →

Will my solar plant run during a power cut?

Not with a plain on-grid inverter. Anti-islanding protection makes it shut down the instant the grid fails, so it cannot energise a line a lineman believes is dead. Running loads through an outage needs a hybrid inverter with battery, which costs meaningfully more — and is one of the commonest reasons two quotations differ. Net metering explained →

How much solar can I install?

It is capped in relation to your sanctioned load or contract demand, with the percentage set by state policy — not by how much roof you have. Check the limit first, then size the plant. Industrial solar →

Control & data

Still not answered?

These are the questions that come up most often. If yours is not here, it is probably a better question — send it across.

ASK

WhatsApp is fine

Send the drawing, the part photo or just the question. We answer technical questions whether or not there is an order in it.

VISIT

Come and see the workshop

Faridabad, Sector 23. Call ahead and we will show you whatever is being built that week.

HONEST

We say when the answer is no

If you do not need the thing, or a different method suits better, that is what you will be told.

On the shop floor

Machines we have built

Photographs from our Faridabad workshop and from customer installations.

workshop-wide.jpgOur workshop, Faridabad
panel-wiring-ferruling.jpgFerruled panel wiring
leak-test-hmi.jpgLeak test HMI
bolt-press-scada-graph.jpgPress force-displacement graph
cnc-retrofit-after.jpgCNC after retrofit
solar-rooftop-plant.jpgRooftop solar plant
Specification

What gets fixed before we cut steel

Where to go next, depending on what brought you here.

If you are looking atStart here
A panel for a plant or machineMCC, PCC, APFC, PLC and LT panel pages
Proving a part sealsLeak testing machine overview
Proving an assembly was made rightBolt press with SCADA monitoring
A hole pattern or threadsDrilling and tapping SPM
An idle CNC machineCNC retrofitting and refurbishment
Cutting an electricity billIndustrial solar and APFC panels
A building services panelAHU, fire fighting, lift and car parking panels

Why we wrote this page

Because the same eight questions arrive every week, usually from people who have been given a quotation and no explanation. A buyer who understands why one quote is cheaper is a better customer than one who simply picks the lowest number — and is far less likely to be disappointed later.

If your question is not here, send it. We answer technical questions whether or not there is an order attached, and the good ones end up on this page.

Questions we get asked

Before you send an enquiry

What is the difference between MCC and PCC panels?

A PCC, or power control centre, distributes incoming power to outgoing feeders. An MCC, or motor control centre, starts and protects motors through starter modules. A plant usually has one PCC and several MCCs.

What does an APFC panel save?

It removes the low power factor penalty on your bill and reduces demand in kVA for the same useful kW, which lowers demand charges. Whether it pays back depends on your current power factor and tariff, which we work out from a recent bill.

Should we use air leak testing or water submersion?

Air pressure decay gives a recordable number and is faster and dry. Water submersion gives a visual verdict and shows where the leak is. Many lines use air to screen and water to investigate failures.

Why do plastic parts fail on a standard leak tester?

They expand under pressure rather than leaking. The internal volume grows and pressure falls, which reads as a leak. Longer settle time, lower pressure, gentle clamping and differential testing against a master solve it.

Is an old CNC machine worth retrofitting?

If the bed casting is sound and way wear is reclaimable, yes — a retrofit costs a fraction of a new machine and delivers in weeks. If the machine has been crashed hard or run without lubrication for years, it is not a candidate.

Will a rooftop solar plant run during a power cut?

Not a plain on-grid system. Anti-islanding protection shuts it down so it cannot energise a line a lineman thinks is dead. Running loads during an outage needs a hybrid inverter with battery.

Do I actually need a VFD?

If the load varies, usually yes — fan and pump power follows roughly the cube of speed. If the motor runs at constant full load all day, a VFD saves no energy, though it still offers soft starting and better control.

What does force-displacement monitoring catch on a press?

Missing components, cross-threaded or off-square bolts, cracked parts, wrong variants and worn tooling — failures that change the shape of the curve without breaking a simple force or position limit.

Get a quote

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