Line vs Load Side of Switches: Industry Standard Terminology
Line vs Load Side of Switches: Industry Standard Terminology
(OP)
My name is Elsa and I’m a new Engineer in the Distribution Operations Center for my company. Recently, my Distribution Ops Manager asked me to reach out to people in the electric utility field regarding terminology used within different organizations. Specifically, we’re looking for standard best practice in the industry with regards to referencing of switches in, and outside of, substations.
We have varying language used to describe the high and low side of a switch. For example:
In Sub Outside Sub
Bus / Line Line / Load
Source side of switch is referred to as Bus within the substation, and Line out on the feeder.
Load side of the switch is referred to as Line within the sub, and Load out on the feeder.
As you can see, there is room for miscommunication and misunderstanding and we are working toward the standardization of common terms used within our enterprise. Are any of you willing to share what terminology is used throughout your organization? I appreciate any input or comments you have to offer.
Thanks in advance for the input!
We have varying language used to describe the high and low side of a switch. For example:
In Sub Outside Sub
Bus / Line Line / Load
Source side of switch is referred to as Bus within the substation, and Line out on the feeder.
Load side of the switch is referred to as Line within the sub, and Load out on the feeder.
As you can see, there is room for miscommunication and misunderstanding and we are working toward the standardization of common terms used within our enterprise. Are any of you willing to share what terminology is used throughout your organization? I appreciate any input or comments you have to offer.
Thanks in advance for the input!






RE: Line vs Load Side of Switches: Industry Standard Terminology
out = load
No more complicated than that.
line/load in my opinion are ONLY to indicate which direction out of a switch/breaker,etc.. to go to find the power source (or the load)
RE: Line vs Load Side of Switches: Industry Standard Terminology
Thanks mcgyvr and anyone else who posts!
RE: Line vs Load Side of Switches: Industry Standard Terminology
I understand the desire to standardize, but I wouldn't get your hopes up. The best tool is an accurate one-line diagram with bus, line, switch and breaker designations that everyone uses and refers to.
RE: Line vs Load Side of Switches: Industry Standard Terminology
For looped systems use bus/line terminology.
I find mixing them; ie line/load and source/bus problematic. The line side can be the load side and the source side can be the bus side.
RE: Line vs Load Side of Switches: Industry Standard Terminology
RE: Line vs Load Side of Switches: Industry Standard Terminology