Missing voltage rating
I am looking at this RF connector.
I see that insulation resistance and breakdown voltage are specified, but no voltage rating:
I have two questions, one functional and one safety. Functionally, what is the maximum DC voltage I can bias this connector at (There is no voltage rating)? Safety wise, assuming this connector was UL recognized (It is not, but let's say it was), is it allowed to exceed the maximum rated voltage if there was one? The UL norm in question is "UL-1971 Connectors for Use in Data, Signal, Control and Power Applications".
2 answers
They don't outright tell you the maximum operating voltage, probably because that would imply a power level beyond what they think anyone would use this connector with. Note that it is intended for 50 Ω transmission lines. 100 VAC would imply 200 W.
There are two clues in how they test the insulation of this connector in production. They apply 100 VDC for 120 s to check for leakage, and 200 VAC for 60 s while verifying nothing breaks. Since these are only applied for very specific limited times, they aren't intending anyone to apply these voltages indefinitely.
I would certainly limit instantaneous voltages to below 100 V, which means no more than 71 VAC sine before any derating. I'd feel reasonably comfortable with 50 VAC. Note that implies 50 W and 1 A. That's well beyond a typical "signal" application this connector seems to be intended for.
As for UL, they don't care about performance of the connector, only that it doesn't catch fire or otherwise hurt something.
Purely by regulation, if the connector is UL listed, is it allowed to use it out of specs if we verify that functionally it is a non-issue, or does that no longer comply with UL?
Whenever a manufacturer or certifying agency makes promises about a device, those promises are always with various parameters within limits as specified in the datasheet, certification document, or whatever. If you violate any of the stated limits, all promises are null and void.
The above doesn't prevent you from successfully using the device while exceeding one or more limits when you're sure you understand their reasons and why they don't apply in your particular case. However, the manufacturer and/or certifying agency are no longer responsible if the device doesn't work right, electrocutes someone, burns down your house, or blows up your fuel tank. Your insurance company may also have a strong case that they are not responsible to compensate your loss since you used the device in an unapproved manner.
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what is the maximum DC voltage I can bias this connector at
I don't see why this shouldn't be treated like any other component that has a maximum voltage stated in its data sheet or documentation. I'm thinking of such devices as (but certainly not limited to) MOSFETs.
They have a clearly stated absolute maximum voltage and they don't have a rated voltage at all. A rule of thumb is that you keep within two-thirds of the absolute maximum for voltage and current. Some folk will say keep within 50%. If you really want to get assured values, ask the supplier.
Safety wise, assuming this connector was UL recognized...
If it were UL recognized you can find/request the UL test document and, that document will state the conditions under which it was approved i.e. there will be limits stated in that document.
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