Zummo Z14 Manuel D'utilisation page 20

 This machine contains 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:
 If the power cord is damaged, it must be replaced by the manufacturer or its service
agent or a similarly qualified person in order to avoid a hazard.
Manual available at
20
:
http://www.zummocorp.com/manuales/z14.pdf