Can anyone tell me if single and three phase borehole systems must be on earth leakage protection circuits?
Can anyone tell me if single and three phase borehole systems must be on earth leakage protection circuits?
Victor - Knowledge is a blessing or a curse, your current circumstances make you decide!
Solar pumping, Solar Geyser & Solar Security lighting solutions - www.microsolve.co.za
I am not sure but I think it might also take into consideration if you have the pump through a controller or not...
Yes the pumps will have some type of electronic control for overload and over pumping.
Victor - Knowledge is a blessing or a curse, your current circumstances make you decide!
Solar pumping, Solar Geyser & Solar Security lighting solutions - www.microsolve.co.za
With the regs as present it would depend on the method of installation but as long as the supply is not on a plug and socket and the circuit only supplies the borehole then it's unlikely it would require RCD protection. Whether it's 3 phase or single phase makes no difference when it comes to RCD requirements.
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Although submersible pumps 7.2.4.4.2 falls under the pools, spa's etc wouldn't this also apply to boreholes.
The regulation 7.2 addresses 'Swimming pools, paddling pools, ornamental pools, spas and fountains'
The purpose of those regs is to provide extra protection for people within these zones.
A borehole wouldn't be classed as a special zone and as I understand it a borehole wouldn't carry the extra risk attached as outlined in bold above.7.2.1.1 The particular requirements of this subclause apply to the basins
of swimming pools, paddling pools, ornamental pools, outdoor spas and
fountains. The requirements also apply to the surrounding zones of all
these basins. In these areas, in normal use, the effect of electric shock is
increased by a reduction in body resistance and contact of the body with
earth potential.
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Justloadit (05-Aug-16)
Was asked this question again this morning , so thought I would resurrect the thread.
There was also a discussion over earthing in another thread pasted below.
Using SANS 10142-1 ed 2
https://www.theforumsa.co.za/forums/...borehole+pumps
My understanding was and still is that a normal Borehole pump does not require earth leakage and the regulation that everyone likes to bring up is actually under the section for swimming pools.
If I am reading section 6.16.5.2 , I would ignore the reference note to clause 7.2.4.4 as the borehole being installed has nothing to do with a swimming pool.
Have pasted the relevant sections below and would be interested to hear comments.
Also interesting is that in Ed 3 we will no longer need to run an earth wire all the way to the pump. What better earth is there then a piece of steel ( pump) suspended 100m deep in the earth surrounded by water.
6.16.5.2 Submersible motors and motors liable to flooding
NOTE See 7.2.4.4 for pump motors used in pools, spas and fountains.
6.16.5.2.1 A submersible motor shall
a) be supplied by suitable marine type flexible cable firmly attached to the
motor,
b) use a cable gland that has an efficient water seal, and
c) be bonded to the earthing system of the installation.
NOTE A portable water pump can have a submersible motor.
6.16.5.2.2 Conductive parts associated with a water pump (such as the
suction pipe, the delivery pipe and the pump casing) shall be bonded to the
earth continuity conductor. In the case of a submersible borehole motor, the
bonding to the delivery pipe shall be made above ground and within 300 mm
of the collar that supports the pipe.
7.2 Swimming pools, paddling pools, ornamental pools, spas
and fountains
7.2.4.4.2 Submersible pumps
7.2.4.4.2.1 Unless otherwise authorized, a submersible pump shall be fed
from
a) a circuit protected by an earth leakage protection device with a rated
earth leakage tripping current (rated residual current) IΔn not exceeding
30 mA, or
b) a class II isolating transformer. The transformer shall have a maximum
open-circuit voltage of
1) 250 V single-phase or 440 V three-phase, if the pump is used in an
ornamental pool or fountain, or
2) 12 V, if used in other applications
I also read it that the regs above apply to submersible pumps in an environment accessible to people such as swimmimng pools, fountains, water features, spas etc so in my opinion a borehole pump would not fall into this category so would not require earth leakage protection.
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