Hello Group,

I don't know who to ask this question to, so I will pass it by the group.

The question I have is about HiPot testing and grounding.

We manufacture a table to which we attach a PDU--power-distribution-unit 
(basically a power bar, but safety certified to EN60950).  The frame of the 
table is metal, and the surface of the table is made of Trespa, a 
non-conductive material.  The PDU is attached to the metal frame of the table, 
under the table surface.

We gang these tables together to make larger work surface on which laboratory 
instruments are operated.  The tables are bolted together.  We will place a UPS 
under the table, and plug the PDU into the UPS.  The cabling from the PDU is 
routed along the metal structure to the UPS.  I am not aware of a specific 
safety standard to apply.  I am familiar with EN61010 and the Canadian / USA 
equivalents.  My question is this:  the table frame is conductive, so should we 
ground the tables to one another with #14AWG ground wires, and then ground the 
table frame back to building ground? Or back to the UPS?  Do we need to perform 
a HiPot test on this system (UPS, PDU, Table)?  Do we need to ensure ground 
bond conductivity to 0.1ohm or less on the metal structure?

We assemble such tables and systems at customer sites, and in the past it was 
our practice to perform HiPot and Ground Bond tests on the table structures 
before they left our facility.  But that was also because we built-in our own 
power outlets into the tables.  These power outlets provided inherent grounding 
of the table frame, and the HiPot test confirmed safe wiring of the outlets.  
We no longer integrate our own outlets, instead, using off the shelf power 
distribution units (PDUs).

FYI, the PDU's are 115VAC / 15A, typically 6 outlets each.  We also use 
European version equivalents, but at 230VAC.


Any assistance or comment would be appreciated,

Many thanks,


Gary

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