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Equipower™ – An Electrical fire safety product


Have you stopped and wondered how come a home /office gets burnt completely due to short-circuit, when it already had short-circuit protection installed?

Reason might be that the short-circuit is not necessarily cause of fire or may be the short-circuit was caused due voltage fluctuations.

But wait…  Fluctuations don’t happen in metropolitan cities, do they.  Yes they do.

EQ

If you have read this above article in newspaper,  short-circuit protection was already installed yet it caught fire.

The main reason is that sparks/fire caused before short-circuit result in fires. 

Whenever a building/ premise is designed , all safety factors are considered from worst case point of view, except for voltage . Voltage is left to equipments capacity to handle over voltage.

Download Catalogue of Equipower

There are fires caused by incidents like neutral open and double phasing incidents, for which there is no formidable solution. The incident occurs very rarely however when it does it causes huge financial losses due to damages to critical equipments

Equipower

Equipoweris comprehensive power protection device which acts as an insurance against power fluctuation that could damage your electrical appliances and electronic devices used in your homes and offices .

Equipowerprotects your electrical appliances and electronic devices against high voltage, low voltage, surges, spikes.  However what sets it apart from other protection devices is the ability to protect your equipment in case of neutral open condition. It can easily protect your equipment from voltage as high as 440V in single phase. Equipower increases longevity of equipments and minimizes the risk of damage.

 

FEATURES Equipower SPD Stabilizer UPS Isolation transformer
Neutral open protection Yes No No No yes
Double phasing protection Yes No No No No
Lightning protection * Yes Yes No No No
Single phasing protection Yes No yes No No
Phase reversal protection. yes No No No No
Over voltage  and under voltage protection yes No yes yes No

Equipower buying process

Find out Capacity of Equipower suitable for your home/ office

Interested to know more about Equipower? Fill up the form below.

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Video blog#1- neutral open and double phasing protection 


 

In this video we talk about a possible problem caused by two over head wires touching each other because of trees and causing damage and how contemporary solutions like stabilizers and SPD will not be able mitigate the problem.

If you have faced similar issues and want solution for it please give us your details in form below:

Or you could also visit our online store to range of products we offer.

Click here to visit our online store

The need for double phasing and neutral open protection in Solar power plant design


Solar inv.jpg

Generally any equipment will get damaged due to 3 primary reasons.

  1. Short-circuit
  2. Lightning or surges
  3. Temporary over voltages.

First 2 reasons are taken care of in design and considered as per worst case scenario.

However safeguards for temporary over voltage are generally not taken, certainly not considered as per worst case scenario.

In secondary side of LT transformer , worst case scenario is 440V in single phase.

It happens more often than expected.

Reasons for 440V coming in your supply

  1. Neutral open condition
  2. Double phasing

Causes of neutral open.

  1. Uneven load distribution
  2. Loose wiring.
  3. Accidental breakage
  4. Maintenance work errors

neutral open

Causes of double phasing

  1. Trees falling on overhead wires
  2. Touching of overhead wires running through trees.

double phasing

Majority of projects are located outside of city limits due to roof space constraints and industry requirements. Such scenarios are very common

Not one of the available solar inverter can handle a continuous over voltage of the above nature and will get damaged resulting in down time.

There is strong need of safeguard against such issue in design stage itself so that such issues can be tackled with min losses.

To illustrate, if there is short circuit or lighting strike, the system is designed to handle it. However for continuous over voltage there is not a single solution that can be offered.

There is infact no solution incorporated for 440V in single phase. Most of integrators rely on the inverters capacity of handling voltage fluctuation, and they will definitely get damaged in such a situation.

This is where it is recommended to take cognizance of potential problem that can be taken care in design stage itself.

We specialise in this area i.e. Neutral open and double phasing protection.

You can see our website www.microsystemservices.com for details on how we can add value to solar field.

Lightning and surge protection


Surge protection

Surge Protection – a topic that has become increasingly important in recent years as got wide presence across industries. Costly electronic equipment, which is sensitive to voltage peaks on the supply, is no longer found only in offices and factories, but in our homes as well.

Nowadays, highly- sensitive data processing, telecommunication and computer networks form the back-bone of worldwide communications structures without which, no company can survive. Machines and production lines are monitored and controlled by electronic equipments programmed for specific purpose. Even many creative services are no longer conceivable without the aid of computers.
Common to all of them is their dependence on clean electrical energy, within tight tolerance limits and on a continuous supply of power around the clock.

Internal Lightning Protection according to IEC
Lightning current consists of a First stroke followed by a number of subsequent strokes. According to IEC 61024 and IEC 61312, wave shape of the first stroke is calculated to be 10/350 μSeconds.

lightning pulse

Approximately 25 to 30 % of failures in electrical/electronic equipments are because of surges created either by a Lightning or because of switching surges as per the data released by leading insurance companies

power survey

Lightning Peak Current and Frequency of strike:

The maximum value of Lightning current can go up to 200 KA as per IEC 61312 which is in the shape of 10/350 μ Seconds.

Lightning Current Distribution:

According to the standards IEC61024 and IEC 61312, during a lightning strike in a building having an external lightning protection, the lightning current reaches the earth termination. A part of Lightning current goes to earth and remaining part gets coupled into the building through conductive media like Steel reinforcement in Concrete, Earth Conductor Metal Parts connected to earth etc.

lightning distribution

The 100% of lightning energy breaks down as follows according to IEC61312:
–  50% of the lightning current will flow through the ground
–  50% of the lightning current will flow over the connected metal parts of the building (gets coupled into the building)
To protect electrical & electronic equipments inside the building, this 50 % of Lightning current which is entering into the building has to be diverted to the metal parts which is connected from outside. (Metal Water pipe, Metal Sewage pipe, Power lines, data lines etc)

Class B: (Class 1 according to IEC 61643 as well as Class C according to VDE0675)

is an arrester which is designed to carry a lightning current of 10/350 μ Sec duration. Important parameters to be taken care are Lightning Impulse current carrying capacity and Voltage Protection Level (Let through or limiting or clamp voltage)
Class C: (Class II according to IEC 61643 as well as Class C according to VDE0675)

is an arrester which is designed to carry a Surge current in the shape of 8/20 μ Sec. Important parameters to be taken care are Maximum or Nominal Discharge Current carrying capacity and Voltage Protection Level
Class D: (Class III according to IEC 61643 as well as Class D according to VDE0675)

is an arrester which is designed to carry a Surge current in the shape of 8/20 μ Sec as well as tested with a voltage impulse in the shape of 1.2/50 μ Sec. Important parameters to be taken care is Voltage Protection Level

connection diagram SPD

SPD’s are made with Spark Gaps, Metal Oxide Varistors(MOV) Silicon Avalanche Diodes(SAD), Gas Discharge Tubes(GDT) or a combination of these devices
Spark Gaps and GDT’s:

These are called as ‘voltage switching type’ SPD’s. The operating voltage can be determined by the distance between the electrodes. Spark gaps are arresters in which two or more electrodes in series are opposed to each other. The electrodes consist of incombustible material (e.g. carbon or tungsten-copper). Spark gap based arresters used in power line between Line and Neutral should be capable of interrupting the Short Circuit Current (also called as follow current)

GDT

Advantages – It can carry Very Large amount of Surge Current for a long Duration
Disadvantage – Need more time to react (about 100 nano sec), high follow Currents
MOV:

(Metal Oxide Varistors) Varistors are ‘Voltage-dependent resistors’ with a highly non-linear V/I characteristic. Their electrical properties arise from a large number of micro-varistors connected in parallel and in series. The transitions between the micro-varistors can age under the influence of over voltages. Varistors are called as voltage clamping type SPD’s

MOV

Advantages – Faster than Spark Gap (approximately 25 nano sec). Limited current carrying Capacity
Disadvantage – Detoriation after every surge. Can create short circuit after a Maximum discharge current flow

Avalanche Diode:

Transzorb diodes (also known as suppressor diodes) are diodes that limit both positive and negative over voltages. Because of their very fast switching performance (in the picosecond’s region) they are well suited for use in precision and data line protection devices. These are also called as voltage clamping type surge arresters

Avalanche diode

Advantages – Very fast response to surges

Disadvantage – Very low surge current carrying capacity

By using Surge arresters at various zone boundaries, Transient over Voltages created due to a Lightning strike or switching surges can be limited below the Voltage Impulse with standing capacities of the equipments in respective zones.

SPD example

Write to us for more queries on queries@microsystemservices.

Also see

1. Does an AVR or surge (spike) suppressor really protect from voltage fluctuations???

2. How  does Servo Stabilizer work?

3. OVCD

About the Author (Click on the image to visit his LinkedIn profile

amit

Troubled by equipment breakdowns???


OVCD ad1

Does an AVR or surge (spike) suppressor really protect from voltage fluctuations???


AVR  means Automatic Voltage Regulation.

What it does is to regulate the mains voltage within a limited range. In the case of your UPS, it boost +12% when the incoming voltage is too low. Let’s say the incoming voltage is at 200 volts, the output then goes to 224Volts, +12% of 200 volts, which is still acceptable for most UPSs. When the UPS output reaches let’s say, 230V with the boost mode on, then the UPS sends a command to a component called relay so that the +12% compensation is turned off.

Basically the voltage regulation is a series of power transformers, it can either be step-up transformers or a step-down transformers  They basically do the same thing a 220V to 110V step-down transformer does, or a step-up transformer does, when it gets 110V and transforms to 220V. The UPS senses the incoming voltage and commands a series of relays  to select a different transformer output or “tap”, as they call it.

An automatic voltage regulator can only work within a limited range. Their “taps” are at a fixed rate lets say, +10volts. If the UPS have a 12% voltage trimming option and the incoming voltage reaches 270 Volts, it can only trim 12% of that, which will result in 237 Volts.

Voltage regulator transformer can have as many “taps” as its developer wants, but it makes the unit much heavier, it wastes more energy and generates more heat. It doesn’t matter if the AVR has four “taps” or sixteen taps, it is still slow for suppressing voltage surges
Surge suppression is basically made to protect against high energy and fast rising surges or spikes that can be caused by lightning, electric motors being turned on or turned off, etc. Surges are essentially fast rising spikes and voltage swells are slow rising and low energy in nature. Surge suppression can in some cases reduce voltage swells, but this is not its main purpose.
Surge protection is basically comprised of a component called MOV – Metal Oxide Varistor.

An MOV works at diverting surges to ground. When operating at its nominal voltage, or the mains voltage, the varistor acts like a resistor with its resistance tending to the infinite, so it does not conduct electricity to ground at this state. When there is a fast surge, it instantaneously reacts (in nanoseconds) by decreasing its internal resistance, allowing the excess energy to flow to ground.

The voltage regulator cannot act as fast as an MOV for suppressing high power and fast rising surges and would not be capable of that because of the nature of a power transformer. High energy surges must be diverted to ground and power transformers do not do that. Compared to the speed of an MOV, the voltage regulator is like a turtle.

There are some disadvantages regarding the use of MOVs for suppressing voltage swell. MOVs degrade very fast if frequent voltage swell are imposed to it, it gets too hot and it’s internal chemistry degrades. MOVs are made to react fast and come back to it’s initial state very quickly as well, which happens when a power surge occurs. That’s why manufactures of surge protective devices use an MOV that only triggers itself when the voltage is much higher than the mains voltage. If the MOV starts to conduct too early, it will degrade itself very quickly and on all power grids a relatively high number of fast duration swells, do happen

What an MOV doesn’t do…

An MOV does not provide equipment with complete power protection. In particular, a MOV device provides no protection for the connected equipment from sustained over-voltages that may result in damage to that equipment as well as to the protector device.

An  MOV provides no equipment protection from inrush current surges (during equipment start-up), from over current (created by a short circuit), or from voltage sags (also known as a brownout); it neither senses nor affects such events.

Susceptibility of electronic equipment to these other power disturbances is defined by other aspects of the system design, either inside the equipment itself or externally by means of  a circuit which typically consists of a voltage-sensing circuit and a relay for disconnecting the AC input when the voltage reaches a danger threshold. See OVCD).

In nut shell…

The AVR and the surge suppression solve two different problems. They’re complimentary technologies but do  not ensure total power protection.

The AVR can adjust the voltage of the line within a limited range to compensate for the voltage being too high or too low. However, the AVR does not respond quickly enough or have wide enough compensation to handle surges.

Surge protection is capable of putting huge surge voltages into ground very quickly, but won’t adjust the long-term voltage of the line as the AVR does.

Both however are ineffective against sustained high voltages. in neutral open condition , they themselves will need protection.

Please do give us your feedback

For more queries write to us on queries@microsystemservices.com

 

Also see:

some facts about over voltage

Over Voltage cut off Device

How to protect your equipments from extreme power fluctuations

 

 

Effect of Supply variations on different types of Equipments


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