We use an AEC TrueTemp TC131 Heating Circulator on our Bizzy Bee FFE for ethanol recovery. Over the course of ~2 years, we’ve run into this issue 2-3 times: the connectors on the heating elements inside the junction box become corroded, and eventually become brittle and fall apart. This obviously results in the units’ performance dropping to a snail’s pace and needing replacement (either of the entire unit or the wiring/connectors, both of which we’ve done). We’ve since begun regular preventative inspections inside this box in order to stay ahead of the unit going down–and this is what it looks like currently. not fuxed, but will be eventually. we’ve ordered spares of the wires so are prepared to replace all of these pieces once it’s necessary.
Just trying to see if anyone else has had issues like this with these heaters? Or could theorize what could be causing this issue? I’d love to prevent this from happening at all, if it’s possible. There shouldn’t be any water getting inside of this box, nor is there any sign of water getting in (though it could be as vapor, we are in wet-ass Humboldt county). This white film at the top is interesting too.
Bizzy Bee has been responsive but couldn’t pinpoint the cause, and AEC (owned by ACS Corporate) is infamously tough to get ahold of or get answers from. What do we think comrades?
Have any Electrician’s handy? Check the voltage and amp requirements of the heating element and then check the supply power to ensure the heater is seeing the appropriate amount of juice?
@WolfeXtracts Eureka, CA, so generally high humidity (75% and up ave.) and ocean/bay very close by. i’m considering poking a nitrogen hose into the box next time we seal it up to purge air/humidity. @Concentrated_humbold possibly, the next time we have to switch out the wiring we can try that, good call @plagoo when it works it’s a beast, and performs at a very consistent level. we don’t pay much for repair as we’ve taken to buying these wires/connectors ahead of time from the manufacturer and replacing them ourselves.
updating for the record, and in case it should be valuable info to anyone else using these units:
we used the liquid electrical tape to seal over the connections as recommended, but as you’ll read it didn’t fix much:
as has happened twice before, this unit went to half-power, and then down completely, with the same issue: the connections and posts became brittle, with one of the lead wires disconnecting completely on its own (this lead to half-power operation). our attempts to remove and replace the ring connectors resulted in the posts themselves breaking off–taking the unit down completely.
we had our electrician come in to inspect, and here’s his take:
he thinks our issue is not corrosion from humidity/salt air, but rather an inherent engineering flaw that’s exacerbated by our running the unit as hard as it can be run.
When we inspected the connections pictured, the liquid electrical tape had degraded to powder/blackened bits that came off easily with a cleaning brush–a great rec but just wasn’t up to the job (we’re talking 480V, 48kW after all).
in his opinion, we’ve got a shitload of energy running into not terribly beefy ring connectors, and posts that are on the thin side, so creates resistance, thus heat localized in the posts themselves–a bottleneck effectively–really just not enough conductivity, so the electricity is expressed as heat.
this combined with these connections being right above the heat produced by the heating elements below it, with insubstantial measures to isolate the electrical from this heat, makes for too much heat accumulation inside this junction box, which leads to the stuff we see inside the box–connectors being fairly fused to the posts, which have become brittle due to this heat, and connected in a way that they snap off when trying to remove those top nuts.
it might actually be the case that the insulating seal we painted on with the intention of preventing corrosion may have actually made this heat accumulation worse. Our electrician believes this to be a design flaw and that the junction box in the photo should be designed and built in the first place more like a heat sink, with a larger box and fins to help disperse heat.
he recommended preventative maintenance in the form of removing the contacts, cleaning the posts, and replacing, as well as using SS nuts on the posts vs. what they came with. he also recommended that if we do apply any brush-on compounds, to actually use a conductive brush-on compound, and then an non-conductive insulating coating, if at all.
again, just following up, and recording in the case it could help someone else experiencing similar issues, on this exact unit or comparable ones.
