การวิเคราะห์ระบบสายดินเพื่อความปลอดภัยในโรงงานผลิตและบรรจุก๊าซ (ANALYSIS OF GROUNDING SYSTEM FOR SAFETY IN GAS PRODUCTION AND GAS FILLING PLANT)

Abstract

Abstract

The objective of this research is study and analysis of grounding system for safety in gas production and gas filling plant for improving on safety engineering principles. In gas production and gas filling business were design and installation of grounding system according to BS Std 7671-2008 (BS 7671:2008) and IEEE Std 142-2007 (IEEE 142:2007). There are different from the requirements of Thai Electrical Code 2013 (EIT 2001-56). From the survey and grounding resistance measurement sampling total 24 points. The result was shown : (1) analysis of grounding resistance giving compliance with area study' requirements (not exceed 3 ohms), EIT 2001-56 (not exceed 5 ohms), IEEE 142:2007 (1-5 ohms) found that not compliance with the standard was 3 points, 0 point and 0 point. respectively. The suggestion is adding a second ground rod which is copper-clad steel in 3.00 m long by 15.88 mm diameter rod. By the second ground rod is connected to the single ground rod in parallel yield. There are multiple rod is provided to low grounding resistance from 4.90 ohms to 2.84 ohms. (2) analysis of equipment grounding conductor sizing compared between BS 7671:2008 and EIT 2001-56. The result was found that not compliance with both standard were 8 points. The suggestion is consider to increase a size of equipment grounding conductor shall be calculated to ensure values of grounding fault loop impedance not greater than maximum values of grounding fault  loop impedance that can be used. By follow BS7671:2008 the result was shown 1 point to changed a size of equipment grounding conductor from 95 sq.mm to 120 sq.mm. Meanwhile, by follow EIT 2001-56 the result were shown 3 points to  change a size of equipment grounding conductor from 25, 25 sq.mm to 50, 95, 120 sq.mm, respectively. (3) analysis of grounding electrode conductor sizing  found that were accepted as BS7671:2008 and EIT 2001-56 Std. so this chapter is not a recommendation to improve. (4) analysis of bonding jumper found that the main bonding jumper are bonds as being completely but some positions of equipment bonding jumper are not compliance with standard.