喷雾泡沫和塑料恶化
Craig Carter|Posted inGBA Pro帮助on
这不是我参与的项目，而是我与项目经理合作的公司的项目。我认为这将是分享和发布这种经验并了解其他人是否有这种经验的好地方。
以下电子邮件（编辑）来自电工，他在该项目完成6年后发现的内容。
Basically the connectors inside the box have deteriorated.
电子邮件：
你好 - - -
我正在寻找的工作之一是我在深秋的房子里进行了修理。————————————呼吁说车库上的游戏室中的大多数罐头都停止了工作。我确定问题是其中一个固定装置中的不良中性连接，是最接近门的一个。花了一段时间，但是我能够将固定装置从天花板上取出而不会损坏它并访问固定装置侧面的J-box（即使隔热材料试图包围，大部分罐子都沉浸在泡沫绝缘层中带有玻璃纤维的罐头）。不良连接的原因是工厂在固定装置中安装的连接器已经完全恶化。他们看起来好像已经在阳光直射了20年。当塑料分解时，连接器中的金属触点失去了张力，中性触点不再连接。我以前从未见过，只能提出几个可能的原因。1.连接器有缺陷或2.渗入J-box的泡沫发出的气体导致塑料恶化。
有没有人经历过这种情况，如果喷雾泡沫从气体中脱落，这可能是结果吗？
谢谢
Craig
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Replies
从图片很难辨别,但我assumption is an open cell foam encasing the housing? Is the housing IC rated? Is the space above conditioned? Climate zone? It could be a matter of condensation though there doesn’t appear to show signs of oxidizing. How thick is the foam above? I believe 1 1/4” closed cell serves a vapor barrier, not sure on open.
No knockouts used in the box :/
考虑LED光盘灯。3/4英寸的深度，带有颜色渲染选项，易于改造，廉价，允许选项隔离现有腔，并在湿区域进行评分
Most IC rated fixtures I've seen actually say they are NOT rated to be in contact with SPRAY FOAM. You aren't supposed to encapsulate them in spray foam. They are rated to be in contact with things like fiberglass/mineral wool/cellulose, but not what I'd call "fluid applied" insulation like spray foam.
Solvents evaporating from curing plastics and cause problems like you see here. A classic example is stuff around newly applied silicone caulk, because silicone caulk cures by evaporation of acetone, and that acetone can damage some kinds of materials if they're nearby. I haven't seen spray foam cause degredation like this before though.
That plastic looks more likely to be damaged by heat to me. It's possible it was always loose, never making good contact, and ran hot as a result. Keep it hot over time, and the plastic will degrade and fail similar to what you're seeing in your pics.
账单
感谢您的答复。
连接器是否与泡沫接触？喷雾泡沫会导致管道中的塑性故障，泡沫中的消防阻滞剂和催化剂，以及可能导致的固化热量。由于这个原因，压力下的CPVC管道被隔离 /保护不受喷雾泡沫应用（我认为在地板板 /托梁中的小渗透物的偶然泡沫是可以忍受的）。
I will have to ask the electrician if the foam came in contact with the connectors.
我从来都不是连接器推动的粉丝。
I don’t see a name brand on the connector. One has to wonder if the connector was UL approved when installed.
我没有看到锅灯的名称品牌，如果被列出了。
About 1/3 of the way thru this article it shows a similar looking Wago brand “Wall Nut” connector and states it is not UL listed but the article could be out of date.
https://inspectapedia.com/electric/Electrical_Wiring_Splices.php
我的猜测没有人愿意对这个问题承担责任，证明一个或另一个负责的成本将超过更换可疑连接器的成本。
Seems to me the smart move is to pull all the can lights and replace any other similar connectors before they fail and possibly start a fire.
沃尔塔
感谢您的答复。我有信心执行这项工作的电工，并且是一个质疑固定件应用程序的人，因此请列出他检查的UL列车。我需要问更多问题，因此发布我尚未考虑的内容的原因。您提出了我需要问和欣赏的问题。有人告诉我，他专门要求泡沫船员在泡沫之前将固定装置包裹在玻璃纤维隔热材料中，但我相信泡沫在玻璃纤维下延伸到J-box中...将得到澄清。