Zummo Z06 Nature Manuel D'utilisation page 23

 Some versions of this model have an equipotential terminal in the base to connect the
Earth Tap of other appliances to the Earth Tap of your installation through this
terminal. If you use it, slacken the nuts and washers, couple the Earth Tap cable of
the auxiliary appliance and firmly tighten the nuts and washers again.
This equipotentiality point is indicated with the following symbol:
Manual available at
: http://www.zummocorp.com/manuales/z06nature.pdf
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