仪表防爆及接地系统施工方案(中英).doc

仪表防爆及接地系统施工方案
Construction Scheme for
Instrument Explosionproof and Earthing System
1 编制说明：
在现代工业生产装置中，许多易燃、易爆、易挥发的工艺介质出现在生产流程中，防爆施工对装置的安全运行非常重要；各种工艺参数的检测、显示和控制都实现了自动化、集中化、智能化，特别是集散控制系统（DCS）的广泛应用，对仪表接地系统的要求越来越高。正确完成仪表接地系统，对保证设备及人身安全，保证装置安全运行意义重大。
为了高速优质地完成装置防爆及接地施工任务，特编制本方案。
2编制依据:
2.1设计施工图及其它设计文件。
2.2现行《自动化仪表工程施工及验收规范》。
2.3现行的《电气装置安装工程施工及验收规范》。
2.4现行《自动化仪表工程质量检验评定标准》。
2.5厂商提供的产品安装使用说明书等技术文件。
2.6公司《质量保证手册》、《质量体系子程序》及其支撑性文件。
3.工程概况
工程概况应包括：工程名称、地点、规模、特点、范围、主要技术参数、主要实物工程量、工期要求及投资等。
4.防爆施工：
Explosion-proof Construction:
4.1一般规定：
General Regulations:
4.1.1爆炸和火灾危险区域使用的电气、仪表设备的防爆形式及配线方式必须符合设计要求，并满足使用区域的防爆等级规定。
The style of explosion-proof and wiring for electric equipment and instrument equipment, which used in explosion and fire dangerous areas, must accord with the design requirement and content with explosion proof class stipulation.
4.1.2安装在爆炸和火灾危险区域的仪表、电气设备和材料，必须具有符合现行国家或行业标准中规定的防爆质量技术鉴定文件和防爆产品出厂合格证书。设备、材料的外观应无损伤和裂纹。
Concerning electric and instrumental equipment and material that is installed in explosion and fire dangerous area, their explosion-proof quality technique appraisal document and explosion-proof manufacture certificate must be compliance with the new standard requirement of country or vocation. There aren’t damage and crack in appearance of device and material.
4.1.3在爆炸和火灾危险场所使用的防爆电气、仪表设备，应有铭牌和防爆标志，并在铭牌上标明国家授权的部门所发给的防爆合格证编号。
For the explosion-proof electric and instrumental equipment that is used in explosion and fire dangerous area, the nameplate and explosion-proof mark should appear on the equipment, the number of explosion-proof certificate issued by the department of national accreditation should be provided on nameplate.
4.1.4在爆炸和火灾危险场所安装的正压通风的仪表盘（箱）、接线箱及电气、仪表设备、除本质安全型外，应有“电源未切断不得打开”的标志。
The plus pressure ventilation instrument panel (box), junction box, electric equipment and instrument equipment installed in explosive and fire dangerous area, except the intrinsically safe type, it should has “Do not open when energized” notice.
4.1.5仪表电气线路采用的电缆沟、汇线槽、保护管和仪表连接管路在穿越不同防爆等级的爆炸和火灾区域的分隔间壁时，在分隔间壁外，必须做充填密封。
For trench, cable tray, protection pipe used for instrument electric circuit and instrument connection piping, if they cross the separated room in different explosion-proof class explosion and fire area, filling and sealing should be done outside the separated room.
4.2设备安装
Erecting Equipment:
4.2.1采用正压通风防爆的仪表盘（箱），接线箱，安装后应保证箱内压力维持在不低于设计规定的压力值，当有低压力时,其联锁或报井装置动作应准确、可靠。
For the explosion-proof instrument panel (box), junction box with plus pressure ventilation, after they are installed, the pressure in box should be ensured no lower than the design pressure. the interlock and alarm unit should act correctly and reliably when the pressure is low.
4.2.2采用正压通风防爆的仪表盘（箱）、接线箱，其正压力通风管路必须保持畅通，且不宜安装切断阀。
The explosion-proof instrument panel (box), junction box adopting plus pressure airiness, its plus pressure airiness piping must remain accessible and should not mount shutting off value.
4.2.3在爆炸和火灾危险场所安装的仪表箱、分线箱、接线盒及防爆仪表、电气设备引入电缆时，应采用防爆密封填料进行密封；多根电缆穿一根管时，可用密封盒并用适当填充料密封。外壳上多余的孔应做防爆密封。
For the instrument box, junction box, wiring box ，explosion-proof instrument and electric equipment which installed in explosion and fire dangerous areas, the entrance of cable should be sealed with explosion-proof seal filling. When one conduit contains multiple cable, the entrance can mount sealing box with propriety filling. Do explosion-proof sealing to spare holes in shell.
4.2.4防爆仪表箱、分线箱、接线箱的门（盖）应有弹性密封垫圈，或隔防密封面连接螺栓应均匀紧密，并应有弹簧垫。
Covers should have spring sealing washer for explosion-proof instrument box, junction box, and connection box. And connection bolts and nuts of separating and preventing face shall be tight equably and have spring washer.
4.2.5防爆电气、仪表设备的安装应牢固，内部接线必须正确、牢固，并有防松和防拔脱装置。
The explosion-proof electric and instrument devices shall be installed firmly. Inside wiring must be correct and firm with looseness-proof and shedding-proof unit.
3电气线路安装
Erecting Electrical cable line:
4.3.1穿越不同等级的爆炸和火灾危险区域分隔间壁的电缆沟的密封措施：
Sealing way for trench that crosses separated walls belonging to different class of explosion and fire dangerous areas:
a.电缆沟内充砂密封，可敷设一层电缆，充填一层砂，砂层厚约100mm。电缆全部敷设完后，充砂填满电缆沟。
Method of filling fine sand into trench: filling one-layer sand about 100mm depth after install one layer cable. The trench shall be full of sand after all cable layout.
b.在分界处两侧安装隔板，隔板之间充砂，长度不少于1m。
The separated boards should be fixed at both sides of interface, zone between boards shall be filled with sand, and the length is no less than 1m.
c.在分界处用阻火密封填料充填。
Sealing with fire-resistant filling at the interfaces.
4.3.2汇线槽穿越不同级别的爆炸，火灾危险区域分界处时，可采取的密封措施：
Taking airproof measures where cable tray passes through the interface of different class explosion and fire dangerous areas:
a.在分界处作气密砂封。
Carry out seal with sand at the interface.
b.在分界处用阻火密封填料充填，形成密封阻挡层。
Seal with fire-resistant seal filling at the interface and form sealing and resistant layer.
4.3.3敷设在爆炸和火灾危险区域内的电缆（线）保护管应选用厚壁镀锌管。选用的管件应按危险区域的级别采用合适的防爆结构形式。
Choose thick-wall galvanized conduit as cable protective conduit laid in explosion and fire dangerous areas. Selected pipe pieces should adopt proper explosion-proof structure and type according to requirements of the dangerous areas class.
4.3.4保护管与设备或管件之间的连接应采用圆柱管螺纹连接，螺纹有效啮合部分应在6螺距以上，与设备连接应用锁紧螺母锁紧。螺纹上应涂电力复合脂或导电性防锈脂。不得在螺纹上缠麻涂铅油、缠绝缘胶带或涂其它油漆。
Adopt cylindrical gas thread to connect conduit and devices or pipe-pieces. Make sure that effective engagement is more than six pitches and lock tightly equipments with locknut. The thread shall be painted with electric poly-grease or conductive antirust grease. Not wring hemp ropes, not wring insulated tape and not paint lead oil or other painting.
4.3.5仪表电气线路，在防爆区内不应有中间接头，当必须有中间接头时，应在防爆接线箱内进行，且应连接牢固、紧密，接头良好并有防松和防拔脱装置。
Instrument electrical circuit shall not have middle joint in explosion-proof area. If it is obligatory, joint shall be in the explosion junction box, keep connection hard and tight, have all right electrical conductivity with looseness-proof and shedding-proof unit.
4.3.6线路沿工艺管架敷设时，其位置应在爆炸和火灾危险性小的一侧
When lay line along the process pipe stanchion, layout location should be at the side that possibility of explosion and fire is little.
当工艺管线内爆炸和火灾危险介质的密度大于空气时，应在工艺管道的上方，反之，应在其下方。
When density of explosion and fire dangerous medium in the process pipe is heavier than that of air, its layout location should be above the process pipe; on the contrary, its layout location shall be below.
4.3.7保护管与现场仪表设备连接时，应安装隔爆密封管件并做充填密封，密封管件与仪表设备之间的距离不应大于0.45m。密封管件与仪表之间的连接可采用挠性连接管，并按防爆要求书进行装配。挠性连接管的材质应与使用环境条件相符适合。
When connect protection pipe with instrument equipment at site, the explosion-proof and airtight pipe connectors shall be installed, filled and sealed. Make sure that the distance between airproof pipe connectors and instrument equipment is no more than 0.45m. The flexible pipe can be used to connect airtight pieces and instrument and mount according to explosion-proof instruction book. At meantime, flexible material shall agree with application condition.
4.4本安系统施工：
Construction of Intrinsically Safe System:
4.4.1本质安全线路及其附件，应具有耐久性兰色标记。
The intrinsically safe line and accessories shall be marked with blue wear mark.
4.4.2本质安全线路与非本质安全线路之间应加屏蔽，且保持一定的距离。
Add shield net to separate the intrinsically safe circuit from the non-intrinsically safe circuit and keep some distance between them.
4.4.3本质安全线路中的安全栅、隔离器等关联设备的安装位置，应在安全场所一侧，或置于另一与环境相适应的防爆设备外壳内。需接地的关联设备，应可靠接地。
Safe bars, separators and other related equipments in the intrinsically safe line shall be erected at the side of safe location or into explosion-proof device shell that accords with conditions. Equipments needed earthing shall be reliably grounded.

4.4.4不同系列的本质安全型仪表及本质安全线路的关联设备，必须有国家授权的部门发给的产品生产许可证和防爆合格证，其型号规格的替代，必须经原设计单位以文件形式确认。
For related devices of various series intrinsically safe instruments and lines, their manufacture’s license and explosionproof certificate, approved by national authority department, must be provided. If want to replace them, their specifications and types must be approved by primary design unit in form of files.

5.接地系统施工：
Construction for Earthing System:
5.1一般规定：
General Regulations:
5.1.1仪表接地系统一般分为保护接地、信号回路接地、屏蔽接地和本安系统接地四种。
Instrument earthing system generally comprises of four types: safeguard earthing, signal loop earthing, shield earthing and intrinsically safe earthing
5.1.2仪表系统的各种接地应各成系统，互相分开，各自接地母线，接地干线，分支线之间应彼此绝缘。
All earthlings of instrument system should have its own system, every earthling system shall separate and connect to its own earthing bus. Bus and branchline should be insulated each other.
5.1.3仪表接地系统的接地电阻值，应分别符合各自系统的厂商技术文件或设计文件的要求。
Earthing resistance of instrument earthing system should be compliance with requirements of manufacture’s technical files or design files for respective instrument system.
5.1.4当有防干扰需求时，多芯电缆中的备用芯线应在一点接地。屏蔽电缆的备用芯线与电缆屏蔽层，应在同一侧接地。
When it is needed to prevent disturbance, spare cores of multi-core cable should be grounded at one point. Spare cores of shielded cable and its shield should be grounded at the same side.
5.1.5接地线的颜色应符合设计规定，并设置黄/绿标志。
Color of earthing wire should conform to design regulations and set yellow- green sign.

5.1.6接地系统的连线应使用铜芯绝缘电缆或电线，采用铜质螺栓紧固。仪表盘（箱）、柜内的接地汇流排，应使用铜材，并由绝缘支架固定。接地总干线与接地体之间应采用焊接。
Connection line for earthing system should apply with copper-core insulated cable or wire and fasten on copper bolt and nut. Earthing bus bar inside instrument panel (box) or cabinet shall be made of copper and be fixed by insulated support. Apply welding between earthing mainline and earthing pole.
5.1.7自己制作接地汇流排时，连接螺栓与汇流排之间的连接宜采用在汇流排上攻丝的方式连接。
When fabricate earthing busbar by ourselves, connect bolt with bus bar by tapping thread.
5.2保护接地
Safeguard Earthing
5.2.1用电仪表的外壳，仪表盘、柜、箱、盒和电缆槽，保护管、支架底座等正常不带电的金属部分，由于绝缘破坏而有可能带危险电压者，均应做保护接地。供电电压低于或等于24V的就地仪表、开关等，设计无特殊要求时，可不做保护接地。
All not electriferous metallic parts in normal condition, such as shell of usage-power instruments, instrument panel, cabinet, box, case and cable tray, conduit, support foundation etc., should be performed safeguard earthing if their insulation layers have been damaged and may have dangerous voltage. When design does not require, safeguard earthing for local instrument, switch, etc., whose supply power is no more than 24V, can be ignored.
5.2.2在非爆炸危险场所的金属盘、板上安装的按钮、信号灯、继电器等小型低压电器的金属外壳，当与已接地的金属盘、板接触良好时，可不做保护接地。
All low voltage electrical devices in small size, such as pushbutton, signal light, relay etc., fixed on metal panel and board in non-explosion area, if their connection with grounded metallic panel or board is in good condition, their safeguard earthing can be ignored.
5.2.3保护接地系统可接到电气工程低压电气设备的保护接地网上，连接应牢固可靠，不应串联接地。
Safeguard earthing system can connect to safeguard earthing net for electric engineering low voltage plants and ensure connection reliable and hard. However, forbid executing serial earthing.

5.2.4在建筑物上安装的汇线槽及电缆保护管，当设计文件无只能一点接地的规定时，可多点接地
For cable duct and protective pipe erected onto building, if design files do not require only one-point earthing, multi-point earthing is available.
5.3信号回路接地：
Signal Loop Earthing:
5.3.1信号回路的接地点应在显示仪表侧，当采用接地型热电偶和检测元件已接地的仪表时，不应再在显示仪表侧接地。
Signal loop earthing should be performed at the side of display instrument. If using well-grounded thermocouple or measuring elements of instrument have been earthed, earthing at the side of display is unnecessary.
5.3.2各仪表回路和系统只应有一个信号回路接地点除非使用隔离器将两个接地点之间的直、流信号回路隔离开。
Every instrument signal loop and system should have only one-point earthing in general, except that using separator to segregate DC signal loop between two earthing points.
5.3.3电磁流量计、涡轮流量计、分析仪表等仪表设备、应按仪表安装使用说明书等厂商技术文件的要求接地
For instruments such as solenoid flowmeter, turbine flowmeter and analyzing elements, carry out earthing according to installation or operation instruction and manufacture’s technique files.
5.3.4信号回路接地可与屏蔽接地共用一个单独的接在系统。
Signal loop earthing and shield earthing can share a single earthing system.

4屏蔽接地：
Shield Earthing:
5.4.1屏蔽电缆（线）屏蔽层的接地应在显示仪表侧，同一线路的屏蔽层应具有可靠的电气连续性，且只能一点接地。
Perform shield earthing for shielded cable at side of display instrument. For the same conduit, ensure shield has reliable electric continuity and earth at one-point.

5.4.2电缆屏蔽层在仪表盘和接线箱接线时，其屏蔽层应用绝缘保护套保护，不得与盘体或箱体接触。
When performing connection inside of instrument panel or junction box, shield should be protected with insulated sheath to prevent it touch panel or box.
5.4.3屏蔽电缆电缆头制作时，若不需将屏蔽引出，应将屏蔽层与电缆护套切断，若需要将屏蔽引出，网状屏蔽应套绝缘管，绝缘管端包在电缆头内，纸状屏蔽应焊接引线。
While making cable terminal, if it is unnecessary to fetch out the shield, cut off shield layer from cable sheath. If necessary to fetch out shield, for net-shaped shield, housing insulated tube and wrapping its end into cable terminal; for papyraceous shield, welding wire is required.
5.4.4屏蔽接地的引出线截面积应不小于1.5mm2。
Wire cross-section area for shield earthing shall be no less than 1.5mm2.
5.4.5当多根屏蔽电缆固定在一起且均需要接地时，向汇流排引线应均匀分布在汇流排所有的连接点上。
When many shielded cables are banded together and all need earthing, connect them equally to joint position of busbar.

5.5本安系统接地：
Earthing for Intrinsically Safe System:
5.5.1本质安全线路本身不接地，但仪表功能要求接地时，应按仪表安装使用说明书和设计要求接地。
Intrinsically safe circuit itself does not ground. If instrument function requires it to ground, carry out earthing according to erection and operation instruction and design requirements.
5.5.2本质安全型仪表系统的接地，宜采用独立的接地系统或接至信号接地系统上，其接地电阻值应符合厂商技术文件和设计的规定。
As to system earthing for intrinsically safe instrument, we’d better adopt single earthing system or to signal earthing system. And its earthing resistance should conform to regulation of manufacture’s technical files and design.
5.5.3当本质安全线路与非本质安全线路共用一个接线箱时，应将其接地系统分开，分别接至各自的接地干线上。
When intrinsically safe system and non-intrinsically safe system share a junction box, their earthing system should be separated, and connect to respective earthing mainline.

5.54本质安全线路接地，应接到接地式安全栅的接地母线上。
. Earthing for intrinsically safe circuit should be connected to earthing bar of grounding isolated amplifier.

6.执行的技术规范、标准、规程和主要质量指标。
6.1执行的技术规范、标准、规程。
6.1.1现行的《工业自动化仪表工程施工及验收规范》。
6.1.2现行的《工业自动化仪表工程质量检验评定标准》。
6.1.3现行的《电气装置安装工程施工及验收规范》。
6.2主要质量指标
装置仪表防爆与接地工程检验率100%，合格率100%。
7.施工技术措施和质量保证措施：
7.1施工人员必须详细熟悉设计文件和厂商随机文件，并接受工号工程师的技术交底，吃透设计意图和操作要领，严格按照设计文件和施工验收规范施工。
7.2按照设计文件的规定，对工程用料进行严格的验收，确保工程用料的规格、型号、质量标准等满足工程需要。
7.3实行限额领料制度，施工人员必须凭工号工程师签发的限额领料单方可到供应部门领料施工，保证工程用料正确无误。
7.4加强技术培训和研讨，对电缆密封接头等操作要求严的施工工艺，要集中研讨，示范操作，使施工人员均能熟练掌握操作步骤和操作要领。
7.5质检人员要对工程中所有的防爆施工和接地工程实行全部检验，严格控制，发现问题及时要求有关人员进行整改，确保施工合格率100%。
7.6在仪表调试过程中，调试人员需拆卸接线箱盖和仪接线盒的盖子时，应及时恢复原状，并保证各密封垫圈的完整和正确。当需要更换垫圈时，其规格和材质必须与原垫圈相同。
7.7防爆设备的防爆密封面应按厂商随机技术文件的要求，安装符合要求的垫片，涂抹导电性防锈脂。
7.8接地极、接地母线和接地干线埋设时，应以甲方工程管理部门及监理单位的认可，并及时作好隐蔽工程记录。
8.安全施工措施：
8.1电动施工设备，如：套丝机、切割机、电焊机等应做可靠接地，防止事故状态下设备和人身受损害。
8.2防爆设备在搬运