3A99859G01好價(jià)格價(jià)格好

3A99859G01好價(jià)格價(jià)格好

3A99859G01好價(jià)格價(jià)格好

dcs系統(tǒng)接地的基本要求 
　　dcs系統(tǒng)接地是為了保證當(dāng)進(jìn)入dcs系統(tǒng)的信號(hào)、供電電源或dcs系統(tǒng)設(shè)備本身出現(xiàn)問(wèn)題時(shí)，可靠的接地系統(tǒng)能承受過(guò)載電流并可以迅速將過(guò)載電流導(dǎo)入大地。接地系統(tǒng)能夠?yàn)閐cs提供屏蔽層，消除電子噪聲干擾，并為整個(gè)控制系統(tǒng)提供公共信號(hào)參考點(diǎn)(即參考零電位)。當(dāng)接地系統(tǒng)發(fā)生問(wèn)題時(shí)(接地電阻過(guò)大，多點(diǎn)接地控制工程網(wǎng)版權(quán)所有，接地線斷線或接地線與高電壓、大電流設(shè)備相接觸等)，會(huì)造成人員的觸電傷害及設(shè)備的損壞，還會(huì)造成dcs系統(tǒng)經(jīng)常“死機(jī)"(或不明原因的“死機(jī)")，大多是因?yàn)榻拥叵到y(tǒng)不良或存在問(wèn)題所引起的。 
　　因此，完善、可靠、正確的接地，是dcs 系統(tǒng)能夠安全、可靠和良好運(yùn)行的關(guān)鍵。
d cs系統(tǒng)的接地方法 
　　4.1 分散布置的dcs設(shè)備接地方法 
　　分散布置dcs系統(tǒng)設(shè)備之間的連接一般是網(wǎng)絡(luò)(通訊)線，例如：現(xiàn)場(chǎng)控制站分散到現(xiàn)場(chǎng)，而操作員站位于不同的控制室，分散直徑在500米的范圍內(nèi)，各站點(diǎn)間使用多模光纖或5類雙絞線或dp屏蔽雙絞線等連接。 
　　(1) 使用光纖連接的站點(diǎn)：各站點(diǎn)內(nèi)的接地方法同集中布置的dcs設(shè)備。 
　　(2) 使用5類雙絞線或dp屏蔽雙絞線連接的站點(diǎn)： 
　　(3) 控制室的各類地線先連接到公共連接板，公共連接板通過(guò)接地總干線與公共接地極相連。從公共接地極看過(guò)去，整個(gè)接地網(wǎng)絡(luò)是一個(gè)星型結(jié)構(gòu)。

MKS 1159B  MASS FLOW CONTROLLER RANGE 50 SCCM GAS HE

LEICA 115-000-132    PCB ADAPTER CARD LEICA ERGOLUX

TOKYO ELECTRON () 1110-424046-12    GUIDE, WAFER 3 PEEK

TOKYO ELECTRON () 1110-424045-12    GUIDE, WAFER 2 PEEK

TOKYO ELECTRON () 1110-424044-11    GUIDE, WAFER 1 PEEK

KD Technology  10-1602-50  cover purge ring

FIP 100200218  Fitting PP Tee OD 50 S.W PN10

APPLIED MATERIALS (AMAT) 1950902    ILLUM PS IN AC EXT CABLE ASSY WF730/300

CAT 18-60  FITTING GALVANIZED STEEL UNION REKORD 1/

RIMTEC CORPORATION 18004043    COUPLER, WASH UNIT DRIVE

AXCELIS 17B9807    COVER

AXCELIS 17335120    HEAT SHIELD GASKET

LEYBOLD 172  Serial Number On Label 20077410 Pack of 200

Applied Materials (AMAT) 17002    Depth GAUGE

GSI LUMONICS 170-0099-002    GLASS, SCANHEAD WINDOW

TOKYO ELECTRON () 1386-455100-11    CABLE, SVM DIRVE EXT

TOKYO ELECTRON () 1386-454104-12    CABLE, SVM SIGNAL (ETFE)

LAM RESEARCH (LAM) 13-8092-270    SCREW SHLDR POLISHED SS PKG 4

TOKYO ELECTRON () 1380-101161-11      PULLEY, T170-01313-0 MARK 7/8

LAM RESEARCH (LAM) 13-8000-191    PIN,CLEVIS,BASE PLT.

Applied Materials (AMAT)   12SC32RNG32RNG-72NF  3/4" S-Core Hose

AIRPAX 26267-4-V  F.L. AMPS: 10, MAX.V.: 250, 50/60HZ, 62F Delay, 12.5 TRIP AMPS

APPLIED MATERIALS (AMAT) 248762    FLAG, INTERRUPT VERTICLE

ELECTROGLAS 247650-001      SENSOR, PLATEN TEMP

CAT 2280G03  SOCKET N-2 UPS CHINESE  APART PN-2280G03

NOVELLUS  22-00244-00    FTG,ELB,MALE,1/8"NPT-1/8" TUBE PKG 2

21098426 ERIKS/WEST 21098426  KIT, HTP 12 MONTH

CAT 210104610  GASKET FRONT POSITIONER PNEUMATIC

SEAL FOR BEARING COVER IMPELLER SIDE

DIGI-KEY CORPORATION 209F  9 PIN D CON FEMALE

TOKYO ELECTRON 208-600214-2  PCB-Auto Loader Sensor

MATTSON TECHNOLOGY INC 199-21003-00      PIN, ROBOT ARM ALIGNMENT

APPLIED MATERIALS (AMAT) 1951982    SB116A RS232 CABLE ASSY

APPLIED MATERIALS (AMAT) 3300-92164    PLUG, 1/4 BSPP (0 RING SEALED)

APPLIED MATERIALS (AMAT) 3300-91653 `CLAW, CLAMP

SCP GLOBAL 3270251A    MCS 6 CABLE BOX

SCP GLOBAL 3270071B    MODULE, MEMORY RTD

GENERIC 3237016  PANEL Connections Breathing Air.

ASYST Technologies 3200-1066-01    PCB, ASSY, SENSOR ELEVATOR LIMITS

ASYST Technologies 3200-1023-02    PCB MINI OPTICAL

CAT 320004163  FITTING ELL45  11/2 BSPT 150# GALVANISED

CAT 320003740  FITT DELRIN QUICK INSERT 1/4  ELBOW PMCD

CAT 320003296  FITTING PP NUT & SPACER SET 1/2 OD

CAT 320003295  FITTING PP NUT & SPACER SET 3/8 OD

EDWARDS VACUUM INC. 320001    O-RING, VITON, 53X3MM

APPLIED MATERIALS (AMAT) 3190-51001    CHAIN SST

SEMITOOL 311R0004-505    Manifold, 3/8" valves

LAM RESEARCH (LAM) 31-0010-012    CYLINDER, DUAL SENSE

APPLIED MATERIALS (AMAT) 1951982    SB116A RS232 CABLE ASSY

APPLIED MATERIALS (AMAT) 3300-91653 `CLAW, CLAMP

SCP GLOBAL 3270251A    MCS 6 CABLE BOX

SCP GLOBAL 3270071B    MODULE, MEMORY RTD

GENERIC 3237016  PANEL Connections Breathing Air.

ASYST Technologies 3200-1066-01    PCB, ASSY, SENSOR ELEVATOR LIMITS

ASYST Technologies 3200-1023-02    PCB MINI OPTICAL

CAT 320004163  FITTING ELL45  11/2 BSPT 150# GALVANISED

CAT 320003740  FITT DELRIN QUICK INSERT 1/4  ELBOW PMCD

CAT 320003296  FITTING PP NUT & SPACER SET 1/2 OD

CAT 320003295  FITTING PP NUT & SPACER SET 3/8 OD

EDWARDS VACUUM INC. 320001    O-RING, VITON, 53X3MM

APPLIED MATERIALS (AMAT) 3190-51001    CHAIN SST

SEMITOOL 311R0004-505    Manifold, 3/8" valves

LAM RESEARCH (LAM) 31-0010-012    CYLINDER, DUAL SENSE

DAI NIPPON SCREEN (DNS) 2-9P-00010    CABLE, AXIS Z

FICO 4552061  INTERFACE PRINT 081-35/ARA/18

4400-E0-X02-D00-A-P1-U1-C182 NT INTERNATIONAL 4400-E0-X02-D00-A-P1-U1-C182  FLOW

Veriflo 43700659EX  Pressure Regulator SS

NOTT COMPANY 412935-001  GASKET; 320H0079

PRICE PUMP 4095 I  INCOMPLETE KIT, CHILLER PUMP REBUILD

SYSTENCE 40-5888  HOLDER 125 PLA KGH FRONT

HEATRON 404020-001  240-VOLTS 150-WATTS HEATER

ASYST Technologies 4001-9200-01    SHIELD, SAFETY, LPI

BARDEN 39HDB15  Bearing, ID: 8.88mm, OD: 25.99mm--not in original packaging

KUHNKE 39.120.004  Short-stroke cylinder; Standard Stroke: 4mm; Piston diameter:

APPLIED MATERIALS (AMAT) 3780-01046    SPRING, TORSION

APPLIED MATERIALS (AMAT) 3700-90260    O RING BS 242 101.19 ID X..

APPLIED MATERIALS (AMAT) 3700-04044 Parker   O-Ring ID 1.174 CSD .103; ULTRA PAR

APPLIED MATERIALS (AMAT) 3690-90893    SCR.SHLDR.SKT.HD.6DIA(M5)X12

APPLIED MATERIALS (AMAT) 3690-01153 U-C COMPONENTS F-606  Screw Cap Flat Head 6-

MKS   Valve Exhaust Throttle Valve With High Speed Gear Assembly cracked cover

Liberty 6-300  Tacky Roll Mop

GE 5U4GB  Electric Tube, 5AS4A

Barber-Controller 590  Controller, Temperature

GREENE TWEED 5641-0488-SS592  O-RING INNERDOOR DSQ

GENERIC 551534736  Flexure Spring

CAT 551066400  PLATE PASTIC BASE P/N 520-100-1005

ATMI 542-08-012  BOLT  8-32 X 1/2 TITANIUM 030G0301;

TOKYO ELECTRON () 5-39-15154 ADVANCE SAV-6280-X111TM  ADVANCE SAV-6280-X111TM

DAI NIPPON SCREEN (DNS) 5-39-01819    FITTING, Teflon PILLAR

KOKUSAI 4QOD224227    FIXING RING

DAI NIPPON SCREEN (DNS) 7-F4-31989    FILLER, ASSY

DAI NIPPON SCREEN (DNS) 7-F3-43182    BUSH Mount

AXCELIS 78181    Sensor, Filter Infrared AXCELIS-FUSION

VAT 77949-01    Seat VAT Front Slit Valve

ASCENT 7500008501  BEARING BALL 125ID 313OD 1094W

COMPUMOTOR 746-012-1A  DRIVE STEPPER, C DRIVE