oh-lectro
Newbie level 2
I'm working on a control for a humidifier. As per UL standard UL998 a spacing of 6.4mm is required. I'm doing the PCB layout.
"The spacings between wiring terminals of opposite polarity, between a wiring terminal and an
uninsulated non-current-carrying metal part, or between a wiring terminal and uninsulated live part of
opposite polarity shall not be less than specified in Table 12."
Due to the constraints on the PCB size it is very difficult to maintain the 6.4mm requirement. I am using a terminal block with 5mm spacing center-center of the pin (Screw type).
There is also a clause in the standard that I think might save the day.
“42.4 The spacings in Table 12 at installer wiring terminals shall not apply to bars or straps connected to
such terminals.”
Do bars and straps represent “terminal blocks”? Can anyone explain this clause any further?
"The spacings between wiring terminals of opposite polarity, between a wiring terminal and an
uninsulated non-current-carrying metal part, or between a wiring terminal and uninsulated live part of
opposite polarity shall not be less than specified in Table 12."
Due to the constraints on the PCB size it is very difficult to maintain the 6.4mm requirement. I am using a terminal block with 5mm spacing center-center of the pin (Screw type).
There is also a clause in the standard that I think might save the day.
“42.4 The spacings in Table 12 at installer wiring terminals shall not apply to bars or straps connected to
such terminals.”
Do bars and straps represent “terminal blocks”? Can anyone explain this clause any further?