Delta 21CK018C24 Instruction Manual page 60

● Requirement for ground
☆ Air conditioner is the I class electric appliance, thus please do conduct reliable grounding measure.
☆ The yellow-green two-color wiring of air conditioner is grounding wire and can not be used for
other purposes. It cannot be cut off and be fixed by screw, otherwise it would cause electric shock.
☆ The user must offer the reliable grounding terminal. Please don't connect the grounding wire
to the following places:
① Water pipe；
② Gas pipe；
③ Blowing pipe；
④ Other places that professional personnel consider them unreliable.
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