Surge protecors and how many joules are needed

Status
Not open for further replies.

westom

Distinguished
Mar 30, 2009
20
0
18,570

Two types of protectors exist. The first may be a $4 power strip with some ten cent protector parts. Sells for $25 or $150 under hyped brand names. And does not claim to do any protection in its numeric spec sheets. Most will recommend it because those profits mean lots of advertising. Read its specs. How will its hundreds of joules absorb destructive surges that are hundreds of thousands of joules.

The second type is used in any facility that cannot suffer damage. Lightning is typically 20,000 amps. So a minimally sized 'whole house' protectors starts at 50,000 amps. These type protectors must remain functional every after direct lightning strikes. Do not magically absorb hundreds of thousands of joules. Instead connect that energy short (ie 'less than 10 feet') and harmlessly to earth.

Protection is always about where energy dissipates. Many will avoid that discussion due to advertising and education from urban myths. But protection is always about where those hundreds of thousands of joules dissipate. Either energy is inside hunting for earth destructively via appliances. Or energy dissipates harmlessly outside. Then superior protection already inside every appliance is not overwhelmed.

More responsible companies sell 'whole house' protectors including ABB, Intermatic, General Electric, Leviton, Square D, and Siemens. A Cutler-Hammer solution sells in Lowes and Home Depot for less than $50.

The difference is obvious and simple. Ineffective protectors do not have the always required and dedicated wire that connects to single point earth ground. Ineffective protectors also avoid all discussion about what absorbs surges - earth.

Your phone line already has a 'whole house' protection installed by the telco for free. Because 'whole house' protectors are so effective and cost so much less money. But the protector does not do protection. A protector either connects to protection or does nothing. You are responsible for installing and maintaining what does that protection: single point earth ground. Every wire inside every incoming cable must connect low impedance (ie 'less than 10 feet') to that earthing. Or protection is compromised.

Cable TV and satellite dish need no protector. The coax cable connects direct to earth before entering (often using a $2 ground block). The best protector is only a wire connected short (ie no sharp wire bends, etc) to earth.

If you need protection for any one appliance, then you also need protection for a dishwasher, air conditioner, refrigerator, bathroom GFCIs, digital clocks, etc. Just another reason why money is diverted to what really does protection - one 'whole house' protector and upgraded earthing.

High profit plug-in protectors avoid discussing: A protector is only as effective as its earth ground. No earth ground (ie power strip protectors) means no effective protection. Protection is always about where energy dissipates. Always.

 

NightHawk_12

Honorable
Oct 20, 2012
1
0
10,510
A lot of information there but what was the answer to Jerry4's question?
Almost all (if not all power strip connectors) in the UK have an earth. You seem to suggest earth and ground is the same thing but of course they are not always the same thing and this makes a big difference when talking about lightning induced surges.
I guess you are not a native English speaker and thus I thank you for making the effort to put across your points but it is rather difficult to read.
 

vettepiper

Prominent
Jan 9, 2018
1
0
510
I know this is an old post but that don't matter - info is still relevant.
I can't believe what Nighthawk_12 said - evidently he can't read!
Article was very well written by someone with an good knowledge of electricity.
The answer is in there for jerry4 - one that has a true earth ground.
jerry4 is probably like me - I would have thought that some Walmart or Bestbuy powerstrip thingi is just the thing - wrong!
 

bryan36422

Prominent
Jan 5, 2018
2
0
510


It is often expensive and time-consuming to replace a TV set, so an adequate surge protector may prove a worthwhile investment. An important factor to consider is the level of joules a surge protector offers. Electronic accessories manufacturer Belkin recommends its 1,411 joule model for most TV sets, or its 2,444 joule unit for projection televisions. Most electric experts advocates a minimum level of 1,500 joules for TVs.

 
Status
Not open for further replies.