Forums
New posts
Search forums
What's new
New posts
New media
New media comments
Latest activity
Media
New media
New comments
Search media
Members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Main Forums
Electrical Inspection & Testing Forum
Zs = Ze +(R1 + R2) Where am I going Wrong
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support Talk Electrician Forum:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="gazza96" data-source="post: 72057" data-attributes="member: 993"><p>Hello all,</p><p></p><p>I've got a question about Inspection and Testing, I'm a domestic Installer and have done a fair bit of testing and signing off my own work. This is my first time I've had anything to do with TT systems and need some advice.</p><p></p><p>I have been installing a circuit in a property which is TT, has a Main Switch which is an RCD (100mA) and the circuit I am installing is 32 Amp Type B 60898 MCB with a disconnection time of 0.4s. I'm happy with what I've done, the work is neat &amp; tidy, its not a long circuit so if it was a TNS or TNCS i know the reading would be ok. I am using three leads with the Tester on No Trip, so getting a reading.</p><p></p><p>The Ze is 11 ohms (very good reading for an earth rod), the R1 + R2 is 0.4 ohms but when I do the Earth Fault Loop Impeadence Test the reading is 13.6 ohms</p><p></p><p>This is what you would expect if you do the maths, but when I look at the value permitted (1.16 ohms), it obviously fails.</p><p></p><p>I'm looking at page 103 of 17th Ed OSG.</p><p></p><p>Many thanks in advance for any replies</p><p></p><p>Gazza</p></blockquote><p></p>
[QUOTE="gazza96, post: 72057, member: 993"] Hello all, I've got a question about Inspection and Testing, I'm a domestic Installer and have done a fair bit of testing and signing off my own work. This is my first time I've had anything to do with TT systems and need some advice. I have been installing a circuit in a property which is TT, has a Main Switch which is an RCD (100mA) and the circuit I am installing is 32 Amp Type B 60898 MCB with a disconnection time of 0.4s. I'm happy with what I've done, the work is neat & tidy, its not a long circuit so if it was a TNS or TNCS i know the reading would be ok. I am using three leads with the Tester on No Trip, so getting a reading. The Ze is 11 ohms (very good reading for an earth rod), the R1 + R2 is 0.4 ohms but when I do the Earth Fault Loop Impeadence Test the reading is 13.6 ohms This is what you would expect if you do the maths, but when I look at the value permitted (1.16 ohms), it obviously fails. I'm looking at page 103 of 17th Ed OSG. Many thanks in advance for any replies Gazza [/QUOTE]
Insert quotes…
Verification
Post reply
Main Forums
Electrical Inspection & Testing Forum
Zs = Ze +(R1 + R2) Where am I going Wrong
Top