Rubber coating on transformer - Page 1
Forum section: electronics / beginners

author: kalintox
author_rank: Newbie
timestamp: January 27, 2019, 12:04:34 am
content: I recently bought a UPS APC BV1000I-GR 1000 VA Schuko (a relatively new model), and after setting it up, it started smelling like heated plastic.The UPS is rated at 600W and I measured a max power draw of 368W from the socket during my tests. Upon opening the case, I realized the smell was coming from the rubber coating of the transformer.The UPS has no active cooling and the temps of the transformer easily exceeded 50oC (didn't have a measurement instrument other than my skin)Does anybody know what that coating might be, point to a datasheet of sorts, and some temperature related toxicity standards (diffusion of fumes ...) in this regard?The product functions as intended, and nothing looks dodgy regarding build quality, but the smell after the transformer heats up is nauseating and doesn't go away with time.Other customers had similar problems with other APC UPSs, but the support doesn't seem helpful.No other components look swollen or leaky, so the smell is 100% form that coating.

author: cdev
author_rank: Super Contributor
timestamp: January 27, 2019, 12:41:38 am
content: Depending on its chemistry, rubber and burning elstomers may be various dregrees of unhealthy. many rubbers were vulcanized with accelerators which made the rubber emit dangerous compounds called n-nitrosamines. Starting around 20 years ago, the EU, and so for the most part Asia, except maybe South Korea and some other Asian countries, there I dont know, to varying degrees regulated the amount of these extremely carcinogenic chemicals in rubber products but the US and generally the Americas did not. This is why all tire warehouses, stores, etc, should have aggressive ventilation year round, if they care about their employees..Many rubber products continue to emit these n-nitrosamines - due to how they were cured, indefinitely, for the life of the products.. and even after they are recycled - (also rubber and especially 'crumb rubber' stored in large quantities can and sometimes does spontaneously combust!) So if your rubber came from a fairly recent European recycling stream or was made in Europe its significantly less likely to be dangerous (its my understanding that they completely redid their chemistry in the EU) but still may not be so healthy to have around, especially if it gets hot where it is. Also another thing I know is that some chemicals found in rubbers act as agonists of the aryl hydrocarbon receptor. (or "AHR" for short, otherwise known as the dioxin receptor) Which means they may be carcinogenic because of that, not just the n-nitroso compunds (which are also found in hair dyes tobacco, and some other products).Note my discussion is not about any specific product its about rubber and similar elastomers, their fumes when heated, health risks, and related issues.Quote from: kalintox on January 27, 2019, 12:04:34 amHeated plastic fumes also may be very unhealthy because of endocrine disrupting chemicals widely used in plastics (EDCs) which also may be obesogenic.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: January 27, 2019, 01:35:38 am
content: Clearly they put it on to reduce transformer lamination buzz. Most transformers these days are fused probably TIG. What’s the bet it wasn’t fused across laminations.Maybe scraping it off but there again it could start buzzing? Maybe a cooling fan will help? Maybe a combination. But if it’s new complain get a replacement or a different mfgr unit.Sent from my iPhone using Tapatalk

author: james_s
author_rank: Super Contributor
timestamp: January 27, 2019, 02:39:36 am
content: Surely it would stop stinking eventually? Maybe run it outdoors for a couple weeks? I have to wonder why the transformer is getting that hot though. The UPS's I've had only ran the transformer when power was lost.

author: cdev
author_rank: Super Contributor
timestamp: January 27, 2019, 07:28:05 pm
content: A transformer thats not under load shouldn't get so hot. Something is not right, maybe you got a defective unit, maybe it has an internal short, or the batteries they supplied were defective, or something.Also, most manufacturers don't userubberfor transformers, they use specific kinds ofvarnish.The better transformer manufacturers use a vacuum/pressure chamber and immerse it in varnish while pulling out air so there is a negative pressure that removes air, then they let the air back in and pressurize it so it absorbs additional varnish, then they dry it out in an oven for several hours at least.It smells for a while but that smell goes away, are you absolutely certain its coated with rubber and not varnish?

author: Zero999
author_rank: Super Contributor
timestamp: January 27, 2019, 07:57:34 pm
content: Most organic material give of nasty, cancerogenic fumes when heated to high enough temperatures, even non-toxic substances such as bread emit noxious smoke.

author: cdev
author_rank: Super Contributor
timestamp: January 27, 2019, 08:06:10 pm
content: All my transformer containing devices get warm to the touch and one of them hums a bit, but they don't stink like the one described. They don't get super hot working at a normal load, either. Getting super hot means they are under more load than they should be, that device should have a bigger transformer.