Ask Helena & Leo

Question: Can you please tell me if there is a specification regarding labeling, and the information that should be included on the label? I am specifically talking about cabinet wiring, labeling each end with To and From locations to assist in troubleshooting, or for people in the field from removing and replacing wires incorrectly. All I can find is that it is up to the manufacturer unless it is UL wiring.

Answer: The topic of labeling wires is found in Section 12, Marking/Labeling of IPC/WHMA-A-620B

In the general section on page 12-1 it states: “Marking is not required unless specified on the controlling document.”, and “If marking method has not been specified by the controlling document, any marking method that meets the requirements of this section is acceptable.”

The content of what is on the label must be defined on the drawing or controlling documents, i.e., the prints. Typically the basic information on the labels is the part number and revision of the product, the serial number of the assembly, the date of manufacture, etc.

Identifying the TO and FROM for each wire is based upon the wire run sheet which is part of the documentation package. This is where you will define the information for each wire in a cable bundle.

Field service technicians must have the correct information to remove and replace wires within the cable. This will come either with the current documentation or will be found through troubleshooting the cable itself by ringing out the cable with a multimeter.