Terminal blocks

I think this is because terminal strips are components of finished products, not finished products themselves. UL will only list complete products/appliances, not the individual components used inside. UL Recognized means the terminal block *could* be used to make a safe consumer product, but since UL hasn't seen the whole product that the terminal block is in, they cannot verify the complete appliance.

Even a product made up 100% of UL *recognized* components may not necessarily qualify for UL *listing*. After all, a UL *recognized* component, used in an application that is beyond it's design, can be dangerous to the end consumer.

daestrom

Yes, your are right. There are tons of "RU" blocks and strips out there and sold to anyone who wants to buy them. What I find strange is that fuse blocks and ground/neutral bus bars can be found UL Listed for field installation. They could certainly be mis-used too.

Perhaps these types of fuse blocks and bars can be listed because they are 'options' for installation in a particular panel. That is, the panel has been listed with certain equipment 'optionally' installed. So those

It would *not* be UL Listed to install a neutral bus bar for a square D panel model 'XXX' into an entirely different model line 'YYY' or into another manufacturer's equipment.

UL can't list a 'generic' terminal block for use in just any old 'generic' installation. The best they can do at that point is 'recognize' that a particular terminal block can be part of a soundly constructed installation.

And of course, *anything* can be misused. But if the field installer follows manufacturer's instructions to install a manufacturer's authorized option, then at least there is some assurance of a safe installation.

daestrom

they all say listed.....

They mislead, or the people that compose the web site info don't know better. Actually all three have blocks that are UL component RECOGNIZED (backward-R U). AB looked promising at first because they said LISTED on the cover page but further inspection reveals otherwise. Thanks though!

installation.

Ok, I see your point, and I think that answers the question. There is no such animal. Thanks, Chuck

Your welcome. Keep in mind, that even if you put together a product composed of nothing but UL *listed* pieces, you cannot say that your product is UL Listed. Similarly, if you build something of UL *recognized* components, the finished product still isn't UL listed or recognized.

But using such UL Recognized components should go a long way towards

daestrom

Actually, my application is a field installed wiring transition in photovoltaic installations. At the end of a series string of pv modules we often like to switch from (exposed 10 AWG USE-2/RWH-2 behind the panels) to (12 AWG THHN-2 in conduit) and bring that to a readily accessible fused combiner box or the inverter. This transition takes place in a UL Listed raintight box large enough for fill requirements. I don't like using wire-nuts or butt connectors or split bolts for this so that leaves me with bulky UL Listed insulated pressure connectors like [Polaris].

Ideally, a neat-clean wire transition would take place on a power block or terminal strip. The real issue is: Will the AHJ inspecting the installation approve it? Less likely if the components are not Listed, but just Recognized, and least likely if not UL at all. But in the end it's the AHJ that decides. While my junction box may not be UL Listed as finished product, it would contain all UL Listed components - and yes, it is possible to misuse UL Listed components, but the AHJ would determine that.

chuck

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