Good video! Thank you. As an electrician myself, we have a saying, don't trust colors, trust your meter. Regarding 120/240 3ø 4w, Phase B is supposed to be your high leg, and that MUST be marked orange, or by other effective means. Also, the utility will often install the high leg on C phase, as the utility meter is looking for a 120 volt connection on the B phase, so if you were to connect the high leg to the B phase on the meter, you would wipe out the meter. Of course then it gets flipped from the meter to the panel. Note: in installations before 1975, the high leg was often the C phase throughout the facility, this can spell danger, during a service upgrade, when, the electricians fail to test voltages before decommissioning the old equipment, and assume the high leg is the B phase, in the process shooting 208 volts through some of the 120 volt equipment when the new service is hooked up. Personally, that's one of the major drawbacks of a high leg delta
Soooo... Did you correct the mis-labled high leg? Also, was the panel itself [properly] labled, indicating "120/240v 3-phase High-leg delta" (or somethingto that effect)? Such marking would be required, since the neutral conductor is present and available (in the panel) and the high-leg could be inadvertently connected-to as single phase load conductor. This is why you ALWAYS verify your phase-to-neutral voltages!
@@johnsandlinjr 408.3 (E) (1) The B phase shall be that phase having the higher voltage to ground on a 3 phase, 4 wire delta connected system. Other busbar arrangements shall be permitted for additions to existing installations and shall be marked. 408.3 (F) (1) A switchboard, switchgear or panelboard containing a 4-wire. delta connected system where the midpoint of one phase winding is grounded shall be legibly and permanently field marked as follows: Caution _____Phase Has _____Volts to Ground. Usually you would write Caution B Phase Has 208 Volts to Ground, however that's not always the case. In installations before 1975, it was common to have the high leg on the C phase, throughout the building. Also, it is possible to have a 480 volt, 3 phase 4 wire delta system. In this case, the high leg is 415 volts to ground. This would be extremely unusual. That being said, whatever the voltage is, and whatever phase it is, we need to mark it.
Good video! Thank you. As an electrician myself, we have a saying, don't trust colors, trust your meter.
Regarding 120/240 3ø 4w, Phase B is supposed to be your high leg, and that MUST be marked orange, or by other effective means. Also, the utility will often install the high leg on C phase, as the utility meter is looking for a 120 volt connection on the B phase, so if you were to connect the high leg to the B phase on the meter, you would wipe out the meter. Of course then it gets flipped from the meter to the panel.
Note: in installations before 1975, the high leg was often the C phase throughout the facility, this can spell danger, during a service upgrade, when, the electricians fail to test voltages before decommissioning the old equipment, and assume the high leg is the B phase, in the process shooting 208 volts through some of the 120 volt equipment when the new service is hooked up. Personally, that's one of the major drawbacks of a high leg delta
That’s right
God bless your soul, I've been looking for this info all morning! Thank you
Soooo...
Did you correct the mis-labled high leg? Also, was the panel itself [properly] labled, indicating "120/240v 3-phase High-leg delta" (or somethingto that effect)?
Such marking would be required, since the neutral conductor is present and available (in the panel) and the high-leg could be inadvertently connected-to as single phase load conductor.
This is why you ALWAYS verify your phase-to-neutral voltages!
someone said that high leg (or wild leg ) should be labled orange ?
That is correct, I don't know how long it's been like this.
High leg in the middle? We put ours on the right
@@johnsandlinjr 408.3 (E) (1) The B phase shall be that phase having the higher voltage to ground on a 3 phase, 4 wire delta connected system. Other busbar arrangements shall be permitted for additions to existing installations and shall be marked.
408.3 (F) (1) A switchboard, switchgear or panelboard containing a 4-wire. delta connected system where the midpoint of one phase winding is grounded shall be legibly and permanently field marked as follows:
Caution _____Phase Has _____Volts to Ground.
Usually you would write Caution B Phase Has 208 Volts to Ground, however that's not always the case. In installations before 1975, it was common to have the high leg on the C phase, throughout the building. Also, it is possible to have a 480 volt, 3 phase 4 wire delta system. In this case, the high leg is 415 volts to ground. This would be extremely unusual. That being said, whatever the voltage is, and whatever phase it is, we need to mark it.
Installed correctly but labeled incorrectly.
Yes, not my panel . I'm leaving it the way I found it. Just showing a high leg reading for those who are curious. Thanks