符合UL等级与防爆标准的编码器：石油天然气钻井应用指南（中英文）

本篇文章将探讨那些经过测试、符合UL等级与防爆标准，即满足石油天然气钻井NEC500要求的编码器。

In this blog, we'll take a look at encoders that are tested to meet UL Class and Division standards, that is, NEC500 requirements for oil and gas drilling.

这些编码器安全标准适用于哪些情况？

Where Do These Encoder Safety Standards Apply?

在许多情况下，相关方可能会要求应用中的编码器必须经过危险环境认证或注册。显然，最终用户可以根据其应用场景判断该区域是持续危险区域、间歇性危险区域，还是存在因其他故障导致该区域变为危险区域的风险。设备原始设备制造商（OEM），例如顶驱设备制造商、绞车设备制造商等，可以确定其设备将在危险环境中运行。保险公司也可能制定相关标准来确定安全要求和编码器认证。这些标准甚至可能高于美国国家电气规范（NEC）/美国保险商实验室（UL）对危险区域编码器的要求。

There are a series of parties that can require encoders in an application to be listed or registered for hazardous applications. Obviously, the end user can determine from his/her application that the area will be deemed continuously hazardous, or intermittently hazardous, or there is a risk of a separate failure causing the area to become hazardous.  Equipment OEMs, such as top drive OEMs, draw works OEMs, etc., can determine that their equipment will be operated in hazardous environments.  Insurers also may have criteria that determine safety requirements and encoder certifications.  These standards may even exceed NEC/UL requirements for encoders in hazardous areas. 

编码器需要哪些认证？

What Encoder Certifications Are Required?

在北美，石油和天然气钻井作业中旋转编码器危险区域认证的最常见要求是Class 1, Division 1和Class 1, Division 2。在加拿大，可能需要cUL CSA或Class 1 Zone 1认证。例如：许多原始设备制造商 (OEM) 要求绞车编码器达到Class 1, Division 1标准，而顶部驱动器通常为Class 1, Division 2。

The most typical requirements for rotary encoder hazardous area certifications in North America for oil and gas drilling are Class 1, Division 1, and Class 1, Division 2.  In Canada,  CSA or Class 1 Zone 1 certifications may be required.  For example:  many OEMs require draw works encoders to be Class 1, Division 1, while top drives are often Class 1, Division 2.

认可编码器与认证编码器

Recognized Encoders vs. Listed Encoders

对于原始设备制造商 (OEM) 而言，有两种选择：他们可以使用  编码器，也可以使用经 UL 认可的编码器。看看 UL 认证编码器和 UL 认可编码器之间的区别和优势：

UL认证“简单”是指，UL认证的编码器可供OEM厂商或最终用户使用，并可应用于各种机器。但是，UL认证编码器（尤其是Class I, Division 2编码器）的缺点在于对连接器类型的限制非常严格。通常情况下，唯一可用的连接器类型是接线盒。编码器接线盒可能需要客户在设备打包搬运时重新接线。Avtron XR 编码器具有防接线错误保护功能，因此不会因接线错误而损坏编码器。但显然，如果出现接线错误，客户必须在钻井作业恢复之前纠正错误。

另一方面，（UL 认可的）组件只能由原始设备制造商 (OEM) 安装，并且 OEM 负责评估应用要求和危险防护措施。通常可能需要某种编码器机械保护或整体外壳。但许多钻井电机应用本身就具备这种保护。例如：顶部驱动装置的编码器通常位于制动器上方、制动器盖下方。因此无需添加额外的外壳。UL认可的编码器的最大优势在于它们可以提供更多连接器选项。因此，石油机械 OEM 现在可以制造即插即用的设备，无需重新连接正交编码器——最终用户只需断开配套插头，并在钻机搬迁时重新连接即可。

For OEMs, there are two choices:  They can use a  encoder, or they can use a (UL) Recognized encoder.  Let's look at the differences and the advantages of UL Listed encoders vs. UL Recognized encoders:

UL Listed is "simple," that is, UL Listed encoders can be used by OEMs or end-users and applied to a variety of machines.  But, the disadvantage of UL Listed encoders (especially Class I, Division 2) is that there are extremely tight restrictions on connector types.  Often the only available type is a terminal box.  Encoder terminal boxes can require the customer to rewire when the rig is packed up and moved.  Avtron XR encoders are protected against wiring errors so you won't destroy them with wiring errors.  But obviously, if a wiring mistake is made, the customer has to fix the error before drilling can resume.

On the other hand,  (UL Recognized) components can only be installed by an OEM, and the OEM is responsible for evaluating the application requirements and hazard protection.  Often some sort of encoder mechanical protection or overall enclosure may be required.  But many drilling motor applications already have this protection.  Example: the encoder on a top drive is frequently located above the brake and beneath the brake cover.  So no additional enclosure needs to be added.  The great benefit of Recognized encoders is that they can have many more connector options.  So the oil machinery OEM can now make a plug-and-play machine so that rewiring the quadrature encoder is not required--the end user can simply disconnect the mating plug, and reconnect when the rig is relocated.

等级和分区评级并非安全标准发展的终点——从某种意义上说，它们是早期开拓者。但它们仍在不断更新，并且是北美油气钻井设备编码器要求的重要组成部分。

Class and Division ratings aren't the end of the safety standard road--in some ways they are the early pioneers.  But they continue to be updated and are a huge part of North American oil and gas drilling requirements for encoders. 

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