Hey,
Apricate any thoughts on this issue,
Installed Power Out To External Out Building, New SWA 3 Core 4mm, Short Run. FuseBox 4-Way RCD MS Consumer Supplying 1 Light Circuit, 2 Double Socket On A Radial In Small Shed. Supplied From Main DB (Older Crab Tree Star Breaker Consumer).
New Installation Tested Out Perfectly, R1+R2 On All Circuits At Shed DB and SWA Supply. Insulation Resistance Also Clear On All. Issue I'm Running Into Is When Attempting To Do A Zs Test On Anything On The Load Side Of The New Sub Main RCD. It Trips The RCD.
My First Thought Was Earth Leakage Problem, Insulation Resistance On Everything New Is Clear. Tried Disconnecting All Neutrals At Main DB and Neutral On RCD Load Side At Sub Main. So Only Testing From Supply Through DB 1 Out To Said Troublesome RCD At Sub Main. But Still Trips When Carrying Out Zs On RCD Load Side.
Ze At Main DB 0.11 Ohms (0.05ohms L-N), PFC 2.18Ka (4.20Ka L-N)
Zdb At Sub Main 0.17ohms / 1.38Ka
RCD At Sub Main Trip Times 117ms x1, 21.4ms x5
RCD Ramp Test Shows 23mA Trip Current
I'm Using A Megger MFT 1720 Using The 3 lead-low (No-Trip) Setting. I Know Testers Can Introduce Earth Leakage However Never Had This Issue Of My Tester Tripping An RCD Every.
With Knowing What the Zdb and R1+R2 Of The Circuits I Can Calculate Zs To Ensure Values Are Acceptable. RCD Trip Times Both x1 And x5 Are Within Expected Values. So On Paper Everything Is Correct However Something Not Sitting Right With Me With That RCD And Not Being Able To Measure A Zs.
Thinking It Could Be A Issue With The RCD. Have Two Fusebox RCBOs On A Different Job Showing Massively Different Trip Times To The Rest Also, So Make Me Wonder How Good They Are.
Continue reading...
Apricate any thoughts on this issue,
Installed Power Out To External Out Building, New SWA 3 Core 4mm, Short Run. FuseBox 4-Way RCD MS Consumer Supplying 1 Light Circuit, 2 Double Socket On A Radial In Small Shed. Supplied From Main DB (Older Crab Tree Star Breaker Consumer).
New Installation Tested Out Perfectly, R1+R2 On All Circuits At Shed DB and SWA Supply. Insulation Resistance Also Clear On All. Issue I'm Running Into Is When Attempting To Do A Zs Test On Anything On The Load Side Of The New Sub Main RCD. It Trips The RCD.
My First Thought Was Earth Leakage Problem, Insulation Resistance On Everything New Is Clear. Tried Disconnecting All Neutrals At Main DB and Neutral On RCD Load Side At Sub Main. So Only Testing From Supply Through DB 1 Out To Said Troublesome RCD At Sub Main. But Still Trips When Carrying Out Zs On RCD Load Side.
Ze At Main DB 0.11 Ohms (0.05ohms L-N), PFC 2.18Ka (4.20Ka L-N)
Zdb At Sub Main 0.17ohms / 1.38Ka
RCD At Sub Main Trip Times 117ms x1, 21.4ms x5
RCD Ramp Test Shows 23mA Trip Current
I'm Using A Megger MFT 1720 Using The 3 lead-low (No-Trip) Setting. I Know Testers Can Introduce Earth Leakage However Never Had This Issue Of My Tester Tripping An RCD Every.
With Knowing What the Zdb and R1+R2 Of The Circuits I Can Calculate Zs To Ensure Values Are Acceptable. RCD Trip Times Both x1 And x5 Are Within Expected Values. So On Paper Everything Is Correct However Something Not Sitting Right With Me With That RCD And Not Being Able To Measure A Zs.
Thinking It Could Be A Issue With The RCD. Have Two Fusebox RCBOs On A Different Job Showing Massively Different Trip Times To The Rest Also, So Make Me Wonder How Good They Are.
Continue reading...
