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)。
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
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PARTICLE MEASURING SU 14 FILTER OPTIC (LAZER CAL.)
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Trane SEN 0387 Sensor, Cond SAT Tefing Temp-Sen 0387
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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-
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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
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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
