3A99859G01好价格价格好

3A99859G01好价格价格好

dcs系统接地的基本要求 
　　dcs系统接地是为了保证当进入dcs系统的信号、供电电源或dcs系统设备本身出现问题时，可靠的接地系统能承受过载电流并可以迅速将过载电流导入大地。接地系统能够为dcs提供屏蔽层，消除电子噪声干扰，并为整个控制系统提供公共信号参考点(即参考零电位)。当接地系统发生问题时(接地电阻过大，多点接地控制工程网版权所有，接地线断线或接地线与高电压、大电流设备相接触等)，会造成人员的触电伤害及设备的损坏，还会造成dcs系统经常“死机”(或不明原因的“死机”)，大多是因为接地系统不良或存在问题所引起的。 
　　因此，完善、可靠、正确的接地，是dcs 系统能够安全、可靠和良好运行的关键。
d cs系统的接地方法 
　　4.1 分散布置的dcs设备接地方法 
　　分散布置dcs系统设备之间的连接一般是网络(通讯)线，例如：现场控制站分散到现场，而操作员站位于不同的控制室，分散直径在500米的范围内，各站点间使用多模光纤或5类双绞线或dp屏蔽双绞线等连接。 
　　(1) 使用光纤连接的站点：各站点内的接地方法同集中布置的dcs设备。 
　　(2) 使用5类双绞线或dp屏蔽双绞线连接的站点： 
　　(3) 控制室的各类地线先连接到公共连接板，公共连接板通过接地总干线与公共接地极相连。从公共接地极看过去，整个接地网络是一个星型结构。

Turck RKM WKM 5711-1M  1M U7377-1 Cable

RHV190-06 VISICS RHV190-06    CABLE, SWITCH TO MONITOR

SPEARS PVCI D2467  reducer FPT Bushing, Size: 1/2" x 1/8", SCH-80, NSF-pw

NITTO KASEI CO LTD   POM BLACK MOD  Cassette Plate

PISCO PL1/4-U10U  PISCO PL1/4-U10U; L CONNECTOR ALIGNER FOCUS UNIT

VEXTA   Motor, Steping, 2-Phase, 0.9 Degrease/Step, DC 24V, 0.21A

INA PAF10070P10  Bushing Bearing; 1651552

Applied Materials (AMAT) NW-50-PR    Over pressure Ring, NW 50

GASFLO PRODUCTS (GFP) NUT-63SS-AP  NUT CGA pkg 6

APPLIED MATERIALS (AMAT) 3700-03076 GREENE TWEED M019000490SC513  0.193"(4.90mm)

ENTEGRIS N2-2  Fitting PFA. Hex. Nipple SCRD. 1/8NPT GAL

DISCO HI-TEC MOGCH037    COIL SPRING F32-35

TOKYO ELECTRON () MB3M87-035737-12    HEATER, VACUUM LINE ASSY 2 1/12

Patlite   Lamp, Hazard, Warning, LED, Blue, 24V DC

SHARP LH2156Z-12  SHARP I.C. RAM

LAMBDA LFS-42-24  Regulated Power Supply

CAT L456831  O-RING AS568-241

WATLOW L021039500U  HEATER JACKET

SMC PNEUMATICS KQ2T06-00  UNION TEE 6MM

KOGANEI KMR-60  Micro Valve Roller-cam

emecanique GV2-AN11  Side Mount Auxiliary Contact

GLT2 (SEEKA) JAI PUNIX INC GLT2 (SEEKA)  SENSOR, FIBER OPTIC

PARKER ED207729  CYLINDER, 1.06X4 DBL ACT END MT SSBIMBA, 1.06DXPSRMY04.0, 250PS

ROHS E31NRFT-LDN-NS-00  MOTOR, ENCODER

VARIAN E30000113      INDICATOR, MOISTURE

Systems Chemistry-Air Liquide 215-164 RIDGID E10512  WELD MACHINE-REP SPRING F

Hokuyo Automatic DM-HB1  Module, Optical Data Transmission Device

NACOM DIB-PVDF  NACOM DIB-PVDF BELLOW PTFE NO VALVE

HITACHI KOKUSAI D4CK13407    PACKING

PFA CV SENSOR PFA  SENSOR, COVER ASSY, PFA

GENERAL ELECTRIC CR353AC4BH1C  MACHINE MAIN CONTACTOR AC., 4 POLE/40 AMPS PER PO

CAT CHP653-NO  AIR CHUCK

THK CF8MUUA  CAM PRT, FOLLOWER

ATEN CE-220L  Controller Video KVM EXTENDER LOCAL UNIT

EBARA C-8811-088-0001    O-ring

METRON  C262028  FEEDING ROLLER

CAT BPJ6  PLUG

NOVELLUS  BB-953562-26    VALVE.MNL

SWAGELOK B-200-1-0157  Male Connector, 1/8 Tube X #10-32

TREBOR AT013  ASSY PILOT VALVE SS40

GREENE TWEED AS-568A-006 CPD E38  O-RING, CHEMRAZ, AS-568A-006, CPD E38

CKD AMG302-X0194  VALVE, AIR OPERATE

DISCO HI-TEC AHAC21430W    SWITCH POWER

SONY AC-LS1A  12.5FT AC POWER ADAPTOR

CAT A43084-A0  CB3084 222 BARATRON BOARD

EBARA A-1500-340-0001    Base Assy

HPS-MKS 9515-0270  HTR1.5,INS,FLG/HOSE,0DP0

AMPHENOL (AMP) 94V-0  Connection, Combination Line

CAT A43084-A0  CB3084 222 BARATRON BOARD

EBARA A-1500-340-0001    Base Assy

HPS-MKS 9515-0270  HTR1.5,INS,FLG/HOSE,0DP0

AMPHENOL (AMP) 94V-0  Connection, Combination Line

HPS 9335-0038  Insulation Jacket--not in original packaging

906310257 STANLEY 310257  Kit, Repair for Power Cylinder

TERADYNE INC 885-095-12    CABLE, JUMPER STP TIMED

LEYBOLD 88321  SEAL, CTRING ASSY

LSPC 865-5231-09  87030-05 9452 CIRCUIT FLEX 93 OHM

DELL 83VKG  VOLTAGE REGULATOR MODULE; 5100378-0400

CAT 830100138  Stud Weld 5/8  UNC (YORK).

AVIZA TECHNOLOGY 815019-263 McMaster-Carr MB0375-015  Washer, Spring, Belleville

SIC ELECTRONICS 9033-1100 Isolation POPET O-ring *** 20 PACK ***

Applied Materials (AMAT) 0720-03116 CONN HSG PLUG 18POS RECT PLSTC METRIMATE ***

Applied Materials (AMAT) 0720-90392 CONNECTOR, SMA FIBRE-OP ***2 PACK***

EOS Technology  WS321  SLIT， BEAM WIDTH CHAMB

Heater, Overload, W32 10LH, 20LH, 30LH

VGA-FEMALE-DL-DVI-I-ADAPTER VGA-FEMALE-DL-DVI-I-ADAPTER  Adaptor VGA(FEMALE) TO 

LANDIS & GYR VALVE-25  VALVE TWO WAY FOR STEAM

Toner TGT4-17dB  4-Port 1-GHz Directional Coupled Tap; 17dB

PARTICLE MEASURING SU 14  FILTER  OPTIC (LAZER CAL.)

TAIYO SH3-D12-1    CYLINDER, SILKYCHUCK

Trane SEN 0387  Sensor, Cond SAT Tefing Temp-Sen 0387

APPLIED MATERIALS (AMAT) 0021-09718    LINER,SLIT VALVE

APPLIED MATERIALS (AMAT) 0020-82508    SHIELD, TUBE LONG

APPLIED MATERIALS (AMAT) 0020-77292    MAIN CUP

APPLIED MATERIALS (AMAT) 0020-45144    BUSHING, REAR

APPLIED MATERIALS (AMAT) 0020-41081    INSERT, PROC CH. INSIDE T.C. REMOVABLE

APPLIED MATERIALS (AMAT) 0020-20852    COVER, HEATSINK TOP

APPLIED MATERIALS (AMAT) 0020-09240    BUFFER, CASSETTE MALE

APPLIED MATERIALS (AMAT) 0020-06983    Housing Slider

APPLIED MATERIALS (AMAT) 0020-04289    Contract Strip

APPLIED MATERIALS (AMAT) 0015-35278    STUD MODFIED 3/8-16X2.85 SST

APPLIED MATERIALS (AMAT) 0050-31384    PLUMBING,WELDMENT ADAPTER UNIVERSL GAS

APPLIED MATERIALS (AMAT) 0050-27589    HOSE ASSY, FACILITY WATER SUPPLY RMTCLN-

APPLIED MATERIALS (AMAT) 0050-08473    HOSE ASSY, INPUT, RF GENERATOR

APPLIED MATERIALS (AMAT) 0040-21704    Manifold, Single Top Oulet

APPLIED MATERIALS (AMAT) 0021-78830    SPRING, LEAF

APPLIED MATERIALS (AMAT) 0021-77357    FLAG, STOPPER ASSY, SCRUBBER 300

APPLIED MATERIALS (AMAT) 0021-21977    POLYMER INSERT

APPLIED MATERIALS (AMAT) 0150-91740    F/O,SPARES TF,1500MM/SMA -SMA

APPLIED MATERIALS (AMAT) 0150-90421    FO, 33C.Tx/33A.Tx 1900MM LG

APPLIED MATERIALS (AMAT) 0150-35581    CABLE ASSY 10 TORR MANOMETER

APPLIED MATERIALS (AMAT) 0150-20041    CABLE ASSY, DI/O STEPPER CONTROLLER

APPLIED MATERIALS (AMAT) 0150-09938    CABLE, ASSY, OPERATOR CONTROL, 5000 MK

APPLIED MATERIALS (AMAT) 0150-04094    CABLE ASSY 300MM ECP WFR LDR E84 I/F EQU

APPLIED MATERIALS (AMAT) 0140-76838    HARNESS ASSY,I/O WAFER SENSOR

BROOK AUTOMATION 0140-745  SWITCH POWER