Distribution Board (DB) surge protection

[phoenix55]

I recently experienced something in my area where due to electricity cable theft, the neutral wasn't working and 400v came through the mains causing surge and damaging a lot of appliances

Is there a device you can install in the DB board that can protect it from main line surges?

 

[Geoff.D]

Not sure if surge arrestors would fully address that sort of fault, but at least you would aware of it and some of the fault currents would be shunted to earth.
Have a look at this site for devices.

There are three zones for surge protection. Each requires protection against surges.
Zone 0 is in turn dived into 2 zones, 0A and 0B, zone 1, zone 2.

A class I SPD could be installed at the point where power enters your premises, but this normally requires the cooperation of the municipality and is very difficult to get done.
But generally, you can get an electrician to deal with protection between zone 0A and zone 0B, Zone 1. Zone 2 is protected by Class III surge arrestors which you can do a should do always anyway on all sensitive equipment. These are surge arrestor plugs and power strips from many suppliers. probably the most reliable is Clearline.
Zone 0B and zone 1 protection is provided as the power enters your building and in your DB.

http://cbi-lowvoltage.co.za/content/surge-protection

Download the pdf datasheet for a very good explanation of what it is all about.

Another site: https://www.phdpowerhouse.co.za/products/surge-protection/db-surge-protection/

See this thread for an example of what should be done as a matter of course on ALL three phase supplies, especially on long spur routes. https://mybroadband.co.za/forum/threads/inverter-to-db-diagram-attached.1014258/

 

[Dee96]

2021 Bump....

With the return of load shedding, we are scheduled for load shedding between midnight and 2:30am which makes turning the main isolator on the DB board on and off very sleep depriving.

In an ideal world, I would like a surge plug for all my devices but I was hoping there is a device I can install directly on the DB board to protect all my devices.
We just got a new fridge and quite frankly, I will be so angry if I have to buy a new one in the next 2 years...

Any suggestions?
What are you guys doing?
Would this help?

Surge arrester CBI ELECTRIC 2 pole

FOR SURGE PROTECTION ON INCOMING POWER SUPPLY IN LIGHTNING PROTECTION ZONES OB TO 1 OR 1 TO 2 IN COMPLIANCE WITH SANS 10142-1

leroymerlin.co.za

 

[krieg]

2021 Bump....

With the return of load shedding, we are scheduled for load shedding between midnight and 2:30am which makes turning the main isolator on the DB board on and off very sleep depriving.

In an ideal world, I would like a surge plug for all my devices but I was hoping there is a device I can install directly on the DB board to protect all my devices.
We just got a new fridge and quite frankly, I will be so angry if I have to buy a new one in the next 2 years...

Any suggestions?
What are you guys doing?
Would this help?

Surge arrester CBI ELECTRIC 2 pole

FOR SURGE PROTECTION ON INCOMING POWER SUPPLY IN LIGHTNING PROTECTION ZONES OB TO 1 OR 1 TO 2 IN COMPLIANCE WITH SANS 10142-1

leroymerlin.co.za

2021 Bump....

With the return of load shedding, we are scheduled for load shedding between midnight and 2:30am which makes turning the main isolator on the DB board on and off very sleep depriving.

In an ideal world, I would like a surge plug for all my devices but I was hoping there is a device I can install directly on the DB board to protect all my devices.
We just got a new fridge and quite frankly, I will be so angry if I have to buy a new one in the next 2 years...

Any suggestions?
What are you guys doing?
Would this help?

Surge arrester CBI ELECTRIC 2 pole

FOR SURGE PROTECTION ON INCOMING POWER SUPPLY IN LIGHTNING PROTECTION ZONES OB TO 1 OR 1 TO 2 IN COMPLIANCE WITH SANS 10142-1

leroymerlin.co.za

That goes into the DB box, you will need even further protection on your valuable devices like those ellies plugs. Try looking at another brand as most of them you simply replace a part that pulls out but that CBI looks solid so you would need to replace the whole unit when it blows.

 

[wingnut771]

2021 Bump....

With the return of load shedding, we are scheduled for load shedding between midnight and 2:30am which makes turning the main isolator on the DB board on and off very sleep depriving.

In an ideal world, I would like a surge plug for all my devices but I was hoping there is a device I can install directly on the DB board to protect all my devices.
We just got a new fridge and quite frankly, I will be so angry if I have to buy a new one in the next 2 years...

Any suggestions?
What are you guys doing?
Would this help?

Surge arrester CBI ELECTRIC 2 pole

FOR SURGE PROTECTION ON INCOMING POWER SUPPLY IN LIGHTNING PROTECTION ZONES OB TO 1 OR 1 TO 2 IN COMPLIANCE WITH SANS 10142-1

leroymerlin.co.za

Takealot.com: Online Shopping | SA's leading online store

South Africa's leading online store. Fast, reliable delivery to your door. Many ways to pay. Shop anything you can imagine: TVs, laptops, cellphones, kitchen appliances, toys, books, beauty & more. Shop the mobile app anytime, anywhere.

www.takealot.com

 

[Dee96]

Takealot.com: Online Shopping | SA's leading online store

South Africa's leading online store. Fast, reliable delivery to your door. Many ways to pay. Shop anything you can imagine: TVs, laptops, cellphones, kitchen appliances, toys, books, beauty & more. Shop the mobile app anytime, anywhere.

www.takealot.com

View attachment 1176758

Thanks but I would like something that could be installed in the db board to protect other appliances like the freezer or even the TV

 

[Dee96]

What you experienced was not an overvoltage surge, it was an overvoltage event. A surge is a short time event. Typically a surge arrestor will not address this type of fault.

When the star point of an unbalanced three-phase is floating you can either experience an overvoltage or under voltage on the phase supplying your house.

In your case, you received almost the full phase-phase voltage.

To protect your installation , and according to SANS all house DB`s should have one but I've yet to see one installed domestically is an Undervoltage / overvoltage relay. They are just expensive but they work really well.

They are very common on Farms and rural areas where farm lines cause these types of issues - usually leaving you with a burnt-out motor or borehole pump.

EZ9C1240 - Voltage relay-40A-1P+Ns- over voltage / undervoltage relay - automatic reclosing | Schneider Electric Global

Schneider Electric Global. EZ9C1240 - Voltage relay-40A-1P+Ns- over voltage / undervoltage relay - automatic reclosing.

www.se.com

Cheapest one I could find :

Studyset Under Voltage Relay,220V Intelligent Adjustable Over and Under Voltage Limit Current Protector Relay Reset Protector 63A

Color:63a Description:Item type: toolPackaging: boxed Brand: SINOTIMER Disconnect capacity: 221-300v-off (adjustable) Model no. : svp-916 40A, svp-916 63A Overcurrent regulation range: 1-63a (default 63A) Power-on delay time :2~10 seconds (default 2 seconds) Product certification :CE RoHS EMC...

pclinkshop.com

but I would rather get something better

Would the studyset relay help when power is restored after loadshedding?

 

[wingnut771]

Thanks but I would like something that could be installed in the db board to protect other appliances like the freezer or even the TV

What I posted was mainly for loadshedding, as it waits 5 mins after the power has come back for things to settle before connecting.

 

[Voicy]

What you experienced was not an overvoltage surge, it was an overvoltage event. A surge is a short time event. Typically a surge arrestor will not address this type of fault.

When the star point of an unbalanced three-phase is floating you can either experience an overvoltage or under voltage on the phase supplying your house.

In your case, you received almost the full phase-phase voltage.

To protect your installation , and according to SANS all house DB`s should have one but I've yet to see one installed domestically is an Undervoltage / overvoltage relay. They are just expensive but they work really well.

They are very common on Farms and rural areas where farm lines cause these types of issues - usually leaving you with a burnt-out motor or borehole pump.

EZ9C1240 - Voltage relay-40A-1P+Ns- over voltage / undervoltage relay - automatic reclosing | Schneider Electric Global

Schneider Electric Global. EZ9C1240 - Voltage relay-40A-1P+Ns- over voltage / undervoltage relay - automatic reclosing.

www.se.com

Cheapest one I could find :

Studyset Under Voltage Relay,220V Intelligent Adjustable Over and Under Voltage Limit Current Protector Relay Reset Protector 63A

Color:63a Description:Item type: toolPackaging: boxed Brand: SINOTIMER Disconnect capacity: 221-300v-off (adjustable) Model no. : svp-916 40A, svp-916 63A Overcurrent regulation range: 1-63a (default 63A) Power-on delay time :2~10 seconds (default 2 seconds) Product certification :CE RoHS EMC...

pclinkshop.com

but I would rather get something better

You're thinking of the right thing, but what you refer to as surges are transients. (usually milli or micro- second events).

Type 1 SPDs are typically used for protection against transients .e.g. lightning strikes.

Type 2 SPD's serve as a voltage clamp. So any "overvoltage events" as you call it, where a floating neutral - or just motors switching on/off in home appliances - increases the voltage, will still be clamped to the 230V* by the rated surge protector... The SPD will change state into a low impedance device and divert the current straight to earth.

(*roughly 20-25% above nominal rated. iov a 230V system will have a 275V rated SPD mounted.)

(Not electrical advice)