作者:Richard Hawkins, MACS撰稿人
作者的注意我写这篇文章有点慢. We had experienced a massive ice storm and were without electricity for eight days. 作为一个结果, a lot of my time has been dedicated to dealing with generator operation and other storm related issues.. I am 确定 a lot of you out there may also have experienced this same storm. Hopefully, life will return to normal for everyone soon.
What should we do if performing an oil balance and only a 1/4 ounce of oil drains from the original compressor (even if the system did have the proper amount in it)? If you just follow oil balancing instructions; you would drain all the oil from the replacement compressor (assuming it contained oil) and put a quarter of an ounce back in and then install the unit. But that presents a problem because with a normal amount of oil in an operating compressor being about 2-to-3 ounces or more, a quarter of an ounce is a very small amount. 作为一个结果, the compressor could suffer from oil starvation during the time that it will take for the full charge of refrigerant (which will hopefully be installed in the system) to move the oil which has been trapped in the evaporator to the compressor.
So, the best thing to do is to remove all the oil from the system by flushing, replace the drier and install the full system charge (8 ounces in this case) in the compressor, rotate it about a dozen times by hand and install it. 这样你就知道了 确定 the system has the proper amount of fresh oil in it. 当然, that could create a bit of an issue if flushing were 不 included when the job was priced out. 尽管这是一个孔管系统, 而且很容易冲水, there is extra labor involved and there is the cost of the flush solvent and asking the customer to pay more might 不 be a viable option. Also, 不 charging for this extra service is going to affect the profitability of the job. 那么，还有其他的选择吗?
我将 不 recommend these because flushing the system and installing the full charge is the only way to be 确定 系统中有正确的数量. This just mentions what some shops have done with success when presented with this issue.
1. They have removed 2 to 3 ounces from the evaporator, lines, or condenser by 小心翼翼地 blowing it out with low pres确定 nitrogen or low-pres确定 dry air. Then they have added these amounts removed from the components to the 1/4 ounce drained from the compressor and put that total amount of fresh oil in the replacement compressor. This is 不 as good as flushing and installing the full system charge, but it does keep the amount of oil in the system the same. 这里有一个词 谨慎 from an R-134a MSDS about mixtures of R-134a and air: “R-134a is 不 flammable at ambient temperatures and atmospheric pres确定. 然而, this material will become combustible when mixed with air under pres确定 and exposed to strong ignition sources. Contact with certain reactive metals may result in formation of explosive or exothermic reactions under specific conditions (e.g., very high temperatures and/or appropriate pres确定s).”
2. They have just put 2-1/4 ounces of oil in the replacement compressor. In this case that would result in about a 25% overcharge of oil in the system, but there is a bit of “wiggle room” when it comes to the amount of oil in a system, so it is likely that amount didn’t have a huge effect on performance. Caution: We are talking about an 8-ounce system here. If dealing with a system with a smaller system such as 4 ounces or less, an extra 2 ounces will have a greater effect.