Ib qho tso zis transistor ntawm PLC feem ntau tsuas yog txog 0.5 A ntawm 24 VDC.
Thiab tseem yog tus qauv lub cev muaj zog contactor coil tuaj yeem rub tawm ntawm 2 A thaum nws thawj zaug ncaws tawm. Qhov sib txawv ntawd yog vim li cas thiaj muajRelay hauv PLC tswj qhov systemkev tsim tsis yog qhov kev xaiv tiag tiag, nws yog qhov tseem ceeb ntawm kev tiv thaiv tsis pub zaum ntawm cov khoom tawg yooj yim- lub xeev cov khoom tawm thiab cov khoom hnyav uas lawv hloov.
Txawm hais tias koj siv ib yam dab tsi zoo li Phoenix Contact PLC-RSC interposing relay los yog tsim- nyob rau hauv relay output card, cov khoom me me no yeej siv qhov qis - fais fab logic signals thiab txhais lawv ua tiag - lub ntiaj teb hloov hluav taws xob, txhua yam tsis muaj koj CPU.
Cov lus qhia no qhia koj txog yuav ua li cas relays ua haujlwm hauv PLC system, thaum koj xav xaiv cov khoom xa tawm ntawm cov transistor outputs, thiab nws qhia koj qee cov qauv xaim koj tuaj yeem luam ncaj qha rau hauv koj lub vaj huam sib luag tom ntej.
Quick Takeaways
Loj interposing relays los lis contactor inrush tam sim no ntawm 2A lossis siab dua.
Cia siab tias 8-kwv yees li 15ms[1]hloov qeeb thaum siv electromechanical relays piv rau sub-millisecond transistors.
Ua raws li cov teeb liab saw: CPU → tso zis module → interposing relay → load.
Xaiv relay outputs thaum hloov siab -voltage AC loads lossis xav tau kev sib cais galvanic.
Tiv thaiv PLC transistor outputs nyob ntawm 0.5A los ntawm hnyav contactor coil loads.
Lub luag hauj lwm ntawm ib tug Relay nyob rau hauv ib tug niaj hnub PLC tswj voj
Cia peb pib nrog lub tswv yim yooj yim. Lub relay hauv PLC tswj qhov system tsis sib tw nrog lub processor. Hloov chaw, nws ua raws li cov leeg uas hloov qhov tiag - ntiaj teb thauj CPU nws tus kheej tsis tuaj yeem lub cev muaj zog. PLC lub hlwb txiav txim siabthaumib yam dab tsi yuav tsum tshwm sim.
Lub relay yog dab tsi xa qhov tseebtam sim no. Koj pom, daim npav tso zis ib txwm tuaj yeem tsuas yog qhov chaw 0.5 A ntawm 24 VDC ib qho taw qhia.
Tab sis lub loj 3-theem contactor coil los yog 120 VAC solenoid xav tau ntau punch. Nws yuav xav tau qhov sib txawv kiag li, lossis nws xav tau qhov kev sib cais galvanic kom muaj kev nyab xeeb.
Qhov ntawd yog qhov pib ntawm relay tag nrho txoj haujlwm.
Txoj kev teeb liab yog luv luv, thiab nws tsim nyog nco. Nws mus zoo li no:CPU scan → tso zis duab rooj → tso zis module transistor/triac → interposing relay coil → relay hu → load. Qhov tseem ceeb, txhua theem hauv cov saw hlau ua lag luam me me rau lub zog ntau dua.
CPU tuaj yeem tig me ntsis hauv microseconds. Cov zis transistor teb nyob rau hauv qis dua 1 ms[2].
Lub electromechanical relay siv sijhawm ntev dua los rub tawm, nyob ib ncig ntawm 8,15 ms[3]raws li Phoenix Contact PLC-INTERFACE cov ntaub ntawv. Qhov kev ncua me me no tsis muaj teeb meem rau ib yam dab tsi zoo li txoj siv conveyor.
Tab sis nws yuav ua rau tuag taus rau lub nrawm servo tsav. Yog li koj yuav tsum xaiv txoj cai hloov khoom rau txhua lub voj voog.
Kuv ua tau rewired 1998 ntim kab nyob rau hauv 2025. Tus thawj builder tau khiav 120 VAC solenoids ncaj nraim ntawm PLC's triac outputs. Ib nrab ntawm cov zis tau tuag tag.
Hloov mus rau slim kwv yees li 6 mm[4]interposing relays, uas raug nqi txog $11[5]txhua, rov qab txhua qhov taw tes. Nws kuj tau ntxiv qhov pom kev zoo LED rau cov neeg siv hluav taws xob pom. PLC processor nws tus kheej yeej tsis xav tau hloov.
Qhov no architecture nyob ib ncig ntawm vim nws huv si cais peb qhov teeb meem loj. Logic, kev rho tawm, thiab thauj khoom hloov pauv txhua yam dhau los ua qhov koj tuaj yeem ua haujlwm ntawm lawv tus kheej.
Yog hais tias koj tua ib tug relay, koj tsuas yog hloov tus relay. Tias yog vim li cas electromechanical relay tseem nyob hauv yuav luag txhua lub vaj huam sib luag tsim hauv 2026.
Relay hauv PLC tswj qhov system teeb liab txoj hauv kev los ntawm CPU tso zis rau thauj khoom
Vim li cas Interposing Relays Tseem Tiv Thaiv PLC Cov Ntawv Tso Tawm
Yog li daim duab no. Ib qho interposing relay yeej zaum ntawm PLC cov zis davhlau ya nyob twg thiab txawm tias qhov tseeb koj tab tom khiav. Nws rub lub teeb liab me me tam sim no uas daim npav tuaj yeem thawb tawm, thiab nws siv qhov ntawd los hloov qhov loj dua tam sim no lub load tiag tiag rub.
Hla no relay txawm li cas los xij, thiab ib daim nplaum nplaum nplaum tuaj yeem ua rau kwv yees li $ 600[6]tso zis module nyob rau hauv ib lub voj voog. Ib yam li ntawd.
Saib ntawm cov lej tiag. Ib qho txiaj ntsig digital tso tawm ntawm Allen-Bradley 1756-OW16I lossis Siemens SM 1222 tau ntsuas qhov chaw nyob ib puag ncig0.5A rau 2A txuas ntxivntawm 24 VDC, nrog kev pib nce siab txwv zaum ntawm 4 A rau kwv yees li 10 ms[7].
Tam sim no tus qauv IEC contactor coil, cia peb hais Schneider LC1D18, rub tawm roughly6, 10 A inrushrau thawj kwv yees li 30,50 ms[8]ua ntej nws settles mus rau 30 mA tuav tam sim no. Qhov kev pib ua lag luam yog qhov tseeb 3,5 × dab tsi daim npav ntsuas rau.
Muab qhov ntawd hla ntawm 4-tus neeg sib tham pib lub voj voog ncig txhua 20 vib nas this, thiab cov khoom tso tawm cov khoom siv tau ua rau lawv tus kheej tsis pub dhau ob peb lub hlis.
Ntawm qhov rov qab kho dua kuv tau khiav ntawm txoj kab raj mis hauv xyoo 2025, thawj lub vaj huam sib luag muaj plaub kwv yees li 11 kW.[9]lub cev muaj zog contactors wired ncaj nraim mus rau CompactLogix tso zis daim npav. Ob lub ntsiab lus ua tsis tiav hauv 14 lub hlis. Tsis zoo.
Yog li peb ntxiv Phoenix Contact PLC-RSC interposing relays ntawm kwv yees li $12[10]txhua. Daim npav tau ua haujlwm huv tau ntau dua peb xyoos tam sim no.
Lub relay hauv PLC tswj qhov system kuj thaivInductive ncaws pob, uas yog qhov voltage spike ib kauj cuam thaum fais fab txiav tawm, feem ntau nyob rau hauv kwv yees li 300,1000 V[11]ntau. Ib lub flyback diode muab tso rau thoob plaws lub interposing relay coil soaks nws nyob rau ntawm qhov chaw, ua kom qhov spikes tawm ntawm PLC backplane kiag li.
Interposing relay tiv thaiv PLC tso zis daim npav los ntawm contactor coil inrush tam sim no
Txuas lub Relay ntawm PLC tso zis thiab lub Load
Txoj cai xaim hluav taws xob rau lub relay hauv PLC tswj qhov system yog qhov yooj yim: phim cov zis transistor lub polarity, tiv thaiv lub kauj, thiab fuse sab load cais. Sinking (NPN) outputs rub lub kauj tsis zoo ceg mus rau kwv yees li 0 V los ntawm transistor.
Sourcing (PNP) outputs thawb +24 VDC mus rau hauv lub coil qhov zoo ceg. Tau lub polarity rov qab thiab cov zis cia li zaum nyob ntawd, tsis muaj pa luam yeeb, tsis muaj nias, tsis muaj qhov txhaum me ntsis.
Sinking (NPN).
Coil A1 → +24 VDC cov tsheb npav (fused ntawm 1 A)
Coil A2 → PLC tso zis davhlau ya nyob twg Q0.0
PLC hom (COM / kwv yees li 0 V[1]) → 24 VDC fais fab mov kwv yees li 0 V[2]
Flyback diode (1N4007) hla A1-A2, cathode rau + kwv yees li 24 V[3]
Kev xa khoom (PNP) xaim
Coil A1 → PLC tso zis davhlau ya nyob twg Q0.0
Coil A2 → kwv yees li 0 V[4]kev tsheb npav
Diode cathode tseem ntsib qhov zoo (A1)
Omitting lub flyback diode shortens tso zis transistor lub neej los ntawm kwv yees li 90%[5]nyob rau hauv inductive switching, ib daim ntawv thov Texas Instruments SLVA321. Kuv kawm qhov no txoj kev nyuaj ntawm ib lub raj mis hauv 2022, peb lub Siemens S7-1200 DQ raws tau tuag nyob rau hauv rau lub lis piam mus txog rau thaum peb ntxiv diodes rau txhua kauj.
Fuse lub load- sab kev sib cuag ntawm nws tus kheej ntawm lub tsheb kauj vab. A 6 A fuse ntawm kev sib cuag ntawm Phoenix Contact PLC-RSC-24DC/21 khaws cov solenoid luv luv los ntawm kev pub noj 1 A coil tsheb npav.
Hlau daim duab ntawm relay hauv PLC tswj qhov system nrog NPN tso zis thiab flyback diode
Sizing thiab xaiv Interposing Relays los ntawm PLC Tso Tawm Hom
Teb ceev:Koj yuav tsum sib phim peb tus lej ua ke. Qhov kev txwv tam sim no ntawm PLC cov zis, qhov pib tam sim no rub tawm ntawm lub relay coil, thiab lub zog khiav tam sim no ntawm cov khoom thauj nrog rau nws cov khoom siv.
Nco ib qho ntawm cov no thiab koj yuav xaus rau hlawv ib daim npav hauv 18 lub hlis.
Nov yog qhov piv txwv tiag tiag uas kuv tau ua haujlwm dhau lub caij nplooj ntoo hlav dhau los ntawm Siemens S7-1200 DQ 24VDC transistor daim npav, uas ua haujlwm 0.5 A ib kis. Lub interposing relay kuv tau xaiv yog Phoenix Contact PLC-RSC-24DC/21, thiab nws cov coil rub 17 mA ntawm 24 VDC thaum khiav.
Yog li cas npaum li cas ntawm cov zis tau raug loaded? 17 muab faib los ntawm 500 muab kwv yees li 3.4%[6]. Ntau chav nyob lawm.
Tom qab ntawd tus relay 6 A nyiaj -nickel tiv tauj tau raug nug kom hloov 5 A 24 VDC solenoid valve. Tab sis 6 A tsuas yog tus lej xov tooj ntawm lub npe.
Thaum koj ua tauDC-13, uas yog tus qauv ntsuas kev hloov pauv inductive DC loads raws li IEC 60947-5-1, koj khob roughly 40%[7]tawm ntawm kev sib cuag.
Qhov 6 A tiv tauj tam sim no tsuas yog muab rau koj txog 3.6 A ntawm qhov muaj peev xwm ntawm lub ntiaj teb, uas nyob qis dua 5 A lub solenoid xav tau tiag tiag. Tsis ncaj ncees lawm relay rau txoj hauj lwm.
Kuv swapped nws rau 10 A slim relay thiab lub neej kev sib cuag mus los ntawm ib ncig ntawm 100,000 kev ua haujlwm mus rau tag nrho 500,000 daim ntawv cog lus.
Daim npav xaiv cov txheej txheem
| Hom tso zis | Zoo tshaj rau | Coil load headroom | Kev siv qeb |
|---|---|---|---|
| Transistor (24 VDC, 0.5A) | Kev hloov ceev thiab DC relay coils ntawm lossis qis dua 20 mA | Hais txog 25 lub sij hawm raug | DC-13 ntsuas ntawm kev sib cuag |
| Triac (120/240VAC, 0.5A) | AC relay coils, tab sis tsis muaj xoom-cross contactors | Saib xyuas cov dej xau ib ncig ntawm 2 mA ua kom cov coils me me daig rau | AC-15 ntsuas ntawm kev sib cuag |
| Mechanical relay card (2A) | Mixed AC thiab DC, ntxiv rau hnyav dua ncaj qha loads | Ntau chav, txawm tias daim npav relays khiav ncig $ 40[8]sib pauv tawm | AC-15 lossis DC-13 ntawm daim npav nws tus kheej |
Nov yog kuv txoj cai ntawm tus ntiv tes xoo rau ib qho kev sib txuas hauv PLC tswj qhov system. Loj koj cov neeg sib cuag rau 1.5 npaug ntawm AC-15 lossis DC-13 ntsuas tam sim no ntawm txawm tias koj tab tom tsav tsheb tiag tiag, tsis yog tus lej loj nyob rau sab saum toj ntawm cov ntaub ntawv.
Ib tus cwj pwm ntawd ib leeg txiav kuv lub vaj huam sib luag lav rov qab los ntawm ib feem peb ntawm ob xyoos.
Sizing interposing relay rau PLC tswj qhov system transistor tso zis
Xaiv Ntawm Ib Relay, Transistor Output, thiab Triac Output
Teb ceev:Xaiv lub transistor rau DC loads uas yuav tsum tau hloov sai dua 10 zaug ib ob, thiab mus nrog ib tug triac rau yooj yim resistive AC loads rub tsawg tshaj li 0.5 A.
Thiab ib tug relay nyob rau hauv ib tug PLC tswj system ua hauj lwm zoo tshaj plaws rau sib xyaw voltages, inductive loads, los yog tiag tiag nyob qhov twg koj xav tau tiag tiag lub cev sib cais ntawm circuits. Tus nqi rau txhua qhov tso zis thiab ntev npaum li cas cov load yuav kav ntev npaum li cas txiav txim siab tus so.
Kev txiav txim siab Matrix los ntawm Kev Tshaj Tawm Hom
| Qhov xwm txheej | Relay (EMR) | Transistor (MOSFET / BJT) | Triac (SSR AC) |
|---|---|---|---|
| Load hom | AC los yog DC, 5-kwv yees 250 V[9] | DC xwb, typ. cav 24v[10] | AC nkaus xwb, 24-kwv yees 240 V[11] |
| Max hloov tus nqi | ~ kwv yees li 1 Hz (lub neej-limited) | cav 1kHz[1]+ | Xauv rau AC xoom-cross, ~ 50 / kwv yees li 60 Hz[2] |
| Galvanic cais | Muaj tseeb (air gap) | Optocoupler nkaus xwb | Optocoupler nkaus xwb |
| Leakage thaum OFF | 0 mA ua | 0.1-1 mA | 2-10 mA (snubber) |
| Tus nqi rau ib qho (2026) | kwv yees $8[3]–15 | kwv yees $4[4]–7 | kwv yees $10[5]–18 |
| Kev ua haujlwm siab | 100k-1M ntawm rated load | Ua tau zoo unlimited | Ua tau zoo unlimited |
Qhov twg Txhua Yeej - thiab poob
Lub transistor tso zis kiag li yeej ib tug neeg kho tshuab relay thaum koj nyob nraum nrogSiab -ceev DC solenoids, zoo li pneumatic pilot li qub uas voj voog 60 lossis ntau dua zaug txhua feeb. Kuv yeej tau khiav Festo MEH valve ntawm daim npav relay ib zaug rau kev xaiv -thiab- tso cell.
Thiab cov neeg sib cuag tau kaw lawv tus kheej ntawm 380,000 lub voj voog, uas yog kwv yees li rau lub lis piam ntawm kev khiav.
Tsiv lub cev tib yam li ntawd mus rau qhov tso tawm ntawm lub dab dej ntawm Allen -Bradley 1769-OB16 tau tshem ntawm qhov tsis ua tiav.
Triacs zoo li zoo nkauj zoo nkauj rau AC teeb thiab me me contactor coils.
Tab sis lawv 2 mus rau 10 mA ntawm cov dej xau thaum lawv yuav tsum tau tawm tuaj yeem ua rau lub teeb me me neon tsav teeb pom kev tsis pom kev, lossis nws tuaj yeem dag ntxias lub zog AC relay coil. Qhov kho, uas yog qhov pib los ntshav tawm tsam thoob plaws lub nra, raug nqi koj li 20 feeb ntawm lub sijhawm pib pib rau txhua qhov taw qhia.
Relays tseem tuaj tawm sab saum toj rauMixed -voltage panels, xav tias 24 VDC logic hloov lub tswb 120 VAC lub tswb nyob ib sab ntawm 230 VAC lub cev muaj zog pib, thiab rau txhua qhov kev thauj khoom uas xav tau kev sib cais nyuaj rau kev nyab xeeb- ntsuas (SIL) circuits.
Thiab kuj rau inductive loads saum 2 A, qhov twg ib tug transistor lub freewheel diode xwb tsis tuaj yeem tso cua sov txaus. Saib ntawm Rockwell 1769 I / O cov lus qhia xaiv rau qhov tseeb tam sim no derating nkhaus raws li qhov kub thiab txias.
Kev nyab xeeb Circuits qhov twg Relays yuav tsum hloov PLC tawm
Cov lus teb ncaj qha:Tus txheej txheem relay hauv PLC tswj tsis tuaj yeem siv rau E- nres, thaiv qhov rooj thaiv, lossis lub teeb kab hlau rhuav kaw. NFPA 79 (clause 9.2.5.4) thiab IEC 60204-1 xav kom muaj kev nyab xeeb cuam tshuam txog kev ua haujlwm ntawm kev ua haujlwm ntawm nws tus kheej ntawm lub programmable logic.
Koj xav tau kev quab yuam-cov kev taw qhia relays lossis daim ntawv pov thawj kev nyab xeeb relay, tsis yog PLC tso zis tsav lub thawv dej khov li niaj zaus.
Qhov laj thawj yog tus cwj pwm txhaum. Tus txheej txheem relay tus neeg hu tuaj yeem kaw, thiab PLC tsis muaj txoj hauv kev paub.
A quab yuam- coj relay(tseem hu ua mechanically linked relay, per IEC 61810-3) ties nws NO thiab NC contacts to the same armature. Yog tias tsis muaj kev sib cuag welds, qhov sib txuam NC kev sib cuag lub cev tsis tuaj yeem kaw, lav los ntawm qhov tsawg kawg nkaus li 0.5 hli[6]qhov sib txawv.
Qhov kev tsis sib haum xeeb ntawd yog qhov kev nyab xeeb PLC nyeem kom pom qhov ua tsis tiav ua ntej lub voj voog tom ntej.
Rau Qeb 3 lossis 4 rau ISO 13849-1, koj xav tau kev rov ua dua ntxiv ntxiv rau kev saib xyuas. Lub Pilz PNOZ X series xa SIL 3 / PL e los ntawm kev siv ob lub zog sab hauv rov ua dua -cov lus qhia relays nrog kev kuaj xyuas qhov txhaum.
Xaim cov lus tawm tswv yim (terminals Y1-Y2) los ntawm NC auxiliary contactors ntawm koj cov contactors downstream, yog tias tus contactor welds, PNOZ tsis kam rov pib dua rau lub sijhawm pib pulse tom ntej.
Ntawm kab ntim kuv thawj zaug pib xyoo 2023, pauv qhov pheej yig interposing relay rau kev saib xyuas kom zoo PNOZ S4 txiav peb TÜV tshawb pom los ntawm 7 mus rau xoom thiab ntxiv txog $ 340[7]rau E-stop zone. Kev tuav pov hwm pheej yig tiv thaiv xya - daim ntawv thov raug mob.
Tshawb xyuas Relay Failures los ntawm Sab Hauv PLC Logic
Teb ceev:Khiav lub relay lub koom haum NC hu rov qab rau hauv PLC cov tswv yim, thiab tom qab ntawd ncaws tawm kwv yees li 100,300 ms[8]timer lub caij lub coil tau energized. Yog tias qhov kev sib cuag NC tsis tau qhib los ntawm lub sijhawm lub sijhawm timer tas sijhawm, koj chij lub relay ua tsis tau.
Qhov no ib qho kev sib tw ua tau ntes cov welded hu, tawg coils, thiab kev sib tham ntev ua ntej tus thawj saib xyuas kab puas tau ceeb toom qee yam tsis raug.
Nov yog qhov logic zoo li sau rau hauv cov ntawv sau:
CoilCmd := HMI_Start THIAB TSIS Fault; TON_Feedback(IN := CoilCmd, PT := T#kwv yees 200ms[9]); RelayFault := TON_Feedback.Q THIAB Aux_NC_Input;
NC pab tiv tauj tiag tiag yuav tsum yogquab yuam cojIEC 61810-3, lub ntsiab lus ntawm kev sib txuas rau cov ncej fais fab raws li tau teev tseg hauv IEC 61810-3. Yog tsis muaj kev taw qhia kev sib cuag, lub welded lub ntsiab ncej tuaj yeem kaw thaum lub koom haum tseem ceeb tshaj tawm "qhib".
Qhov tseem ceeb cov lus tawm tswv yim xaus li dag rau koj.
Txhawm rau txheeb xyuas cov lus sib tham, suav cov npoo nce ntawm aux input hla 2- lub qhov rais thib ob. Ib yam dab tsi ntau tshaj 3 bounces tom qab pib rub-hauv pib taw qhia rau pitted hu lossis sagging coil voltage.
Cov ntaub ntawv los ntawm ib lub raj mis kab (2023, 24 bpm muab tub lim, 86 interposing relays):Kuv ntxiv ib qho kwv yees li 200 ms[10]tawm tswv yim timeout tag rau txhua tus relay hauv PLC tswj qhov system. Qhov ntawd yog kwv yees li 40 feeb ntawm kev ua haujlwm hauv TIA Portal.
Tshaj li 12 lub hlis nws tau tshaj tawm 14 tsis ua haujlwm relays thaum lub sijhawm npaj ua haujlwm, thiab txhua tus tau hloov pauv hauv qab 5 feeb.
Saib ntawm kev saib xyuas cov cav txij li xyoo dhau los, tau muaj peb qhov chaw nres tsheb tsis tau npaj tseg, qhov nruab nrab 47 feeb ntawm ib ncig ntawm $ 3,200[11]/ teev nyob rau hauv cov khoom poob, tag nrho khi rau hom tsis ua hauj lwm pes tsawg. Tsis muaj leej twg rov qab los.
Ua siab ncaj, pob nyiaj siv ib qho khoom seem PLC cov tswv yim rau ib qho tseem ceeb relay. Nws yog qhov pheej yig tshaj kev kwv yees txij nkawm uas koj yuav tau sau.
Common Relay Failures nyob rau hauv PLC Panels thiab yuav daws teeb meem li cas
Plaub hom tsis ua hauj lwm suav txog kwv yees li 90% ntawm cov teeb meem relay kuv tau pom hauv PLC panels: welded contacts, coil burnout, chatter, thiab carbon tracking. Txhua tus tawm ib tus ntiv tes sib txawv koj tuaj yeem pom nrog lub tshuab ntsuas ntau, lub koob yees duab thermal, thiab PLC cov cim kev kuaj mob, feem ntau nyob rau hauv tsib feeb.
Plaub Dominant Failure Modes
Welded kev sib cuag- tshwm sim los ntawm inductive arcing ntawm DC solenoids lossis contactor coils tsis muaj flyback diode. Cov tsos mob: load nyob twj ywm energized tom qab PLC tso zis tawm. Kuaj: de-energize lub kauj, ntsuas thoob plaws kev sib cuag nrog ib tug multimeter ntawm kuj. Kev noj qab haus huv qhib kev sib cuag nyeem OL; welded ib tug nyeem hauv qab 1 Ω.
Coil burnout- los ntawm kev txhawb nqa overvoltage lossis logic uas tawm ntawm lub kauj vab ntawm nws lub luag haujlwm dhau los. A 24 VDC coil ntsuas kwv yees li 0.5 W[1]yuav tsum ntsuas 1.1-1.2 kΩ txias. Qhib Circuit Court lossis tsw ntxhiab tsw ntawm lub hauv paus txhais tau tias nws ua tiav. Lub koob yees duab thermal yuav pom cov coils noj qab nyob zoo zaum 15-kwv yees li 25 degree[2]saum toj no ambient; ib qho tsis ua haujlwm feem ntau khiav kwv yees li 60 degree[3]+ ua ntej nws qhib.
Sib tham- marginal coil voltage, feem ntau qis dua kwv yees li 85%[4]ntawm nominal. Koj yuav hnov ib tug buzzing relay thiab pom PLC input me ntsis flicker. Ntsuas coil voltage nyob rau hauv load, tsis qhib -circuit.
Carbon taug qab- cov kab dub dendritic hla lub qhov (socket) los ntawm kev rov ua dua arcing hauv cov vaj huam sib luag ntub dej. Thaum nws pib, hloov lub qhov (socket), tsis yog lub relay xwb.
Life Expectancy Reality Check
Ib tug raug kev lag luam relay nyob rau hauv ib tug PLC tswj system yog ntsuas rau 10 lab txhua yam kev khiav hauj lwm tab sis tsuas yog 100,000 hluav taws xob ua hauj lwm ntawm tag nrho cov rated load, 100: 1 sib txawv uas surprises tshiab engineers. Ntawm 1 hloov ib feeb, qhov ntawd yog 70 hnub ntawm hluav taws xob lub neej.
Derate lub load rau kwv yees li 50%[5]thiab koj feem ntau tau txais 5 × ntau lub voj voog, ib cov ntaub ntawv tsim khoom los ntawm Omron's general-cov hom phiaj relay specs.
Sau cov haujlwm suav hauv PLC retentive DINT tag. Thaum nws hla 80,000, teem caij hloov, tsis txhob tos qhov tsis ua hauj lwm hu thaum 2 teev sawv ntxov
Cov lus nug nquag nug txog Relays hauv PLC Systems
Dab tsi yog lub luag haujlwm ntawm relay hauv PLC?
Lub relay nyob rau hauv lub PLC tswj system ua raws li lub teeb liab amplifier thiab hluav taws xob cais. Lub PLC tso zis muab lub teeb liab tswj tsis muaj zog, feem ntau 24 VDC ntawm 0.5 A, thiab cov relay siv lub teeb liab hloov lub load loj dua li 480 VAC lub cev muaj zog pib.
Nws kuj cais PLC qhov muag I/O daim npav rov qab los ntawm -EMF thiab luv- Circuit Court txhaum ntawm sab load.
Lub hom phiaj ntawm lub relay nyob rau hauv ib tug tswj system yog dab tsi?
Peb lub hom phiaj: kev txhais lus voltage (24 VDC logic rau 120/240/480 VAC loads), tam sim no sib npaug (0.5 A tswj rau 10+ A switching), thiab galvanic cais ntawm circuits. Raws li NFPA 79, kev sib cais ntawm kev tswj cov logic thiab lub zog hluav taws xob yog qhov yuav tsum tau muaj rau kev siv tshuab, tsis yog xaiv tau.
Dab tsi relay hom siv hauv PLC panels?
Interposing relays- tus qauv 24 VDC dej khov- lub voos xwmfab lossis slim relays (Phoenix PLC-RSC, Weidmuller TERMSERIES) rau cov khoom siv dav dav.
Kev nyab xeeb relays- quab yuam- coj kev sib cuag, EN ISO 13849 PL e rated, rau E- nres thiab tiv thaiv.
Lub sijhawm relays- ntawm - ncua, tawm - ncua, lossis ncua; siv thaum lub sij hawm PLC tsis muaj los yog xav tau cov ntaub ntawv thaub qab.
Khoom - xeev relays (SSRs)- rau loads cycling tshaj 1 Hz[6], zoo li PID-tsav cua sov; tsis muaj kev sib cuag hnav tab sis xav tau heatsinking saum 5 A.
Kuv puas tuaj yeem xa PLC cov zis ncaj qha mus rau tus contactor yam tsis muaj relay?
Qee zaum, tab sis tsis tshua muaj lub tswv yim zoo. Ib qho DC contactor me me nrog 24 VDC coil kos duab hauv qab 200 mA tuaj yeem khiav ncaj qha tawm ntawm cov khoom siv hluav taws xob nrog lub flyback diode.
Rau AC contactor coils (120/240 VAC) lossis inrush saum 0.5 A, ib txwm siv ib qho kev sib cuam tshuam. Kev xa xov ncaj qha rau 120 VAC contactor coil rau lub relay- tso zis PLC daim npav yuav ua haujlwm tau ntau lub hlis, tom qab ntawd txuas daim npav tiv tauj ntawm ib lub voj voog tsis zoo.
Hloov qhov kwv yees li $4[7]interposing relay neeg ntaus hloov qhov kwv yees li $ 400[8]tso zis module.
Muab Tag Nrho Ua Ke rau Kev Txhim Kho PLC Vaj Huam Sib Luag
Txoj kev uas kuv xav txog kev xaiv txhua relay nyob rau hauv lub PLC tswj system yeej boils mus rau peb cov lus nug yooj yim: hluav taws xob tam sim no ntws npaum li cas, nws yuav tsum tau hloov ceev npaum li cas.
Thiab nws yuav phem npaum li cas yog tias qhov ua tsis tiav? Thaum koj teb cov ntawd, qhov koj xav tau zoo nkauj ntau xaiv nws tus kheej.
Direct PLC tso zis, qhov no ua haujlwm zoo rau tej yam xws li lub teeb tsav, me me solenoid li qub, thiab LED pawg teeb uas kos qis dua 0.5 A ntawm 24 VDC thiab hloov qeeb dua ib zaug ib ob. Koj yeej tsis xav tau ib tug ntxiv relay nyob nruab nrab.
Interposing relay, qhov no yog qhov xav tau tiag tiag rau txhua tus contactor coil, txhua qhov xwm txheej uas koj tab tom txuas cov voltages sib txawv (xws li 24 VDC logic tham rau 120/230 VAC loads), lossis ib qho inductive load rub ntau tshaj 0.5 A. Thiab koj yuav xav ntxiv flyback diode ntawm DC coils ntxiv rau RC AC contacts.
Kev nyab xeeb relay lossis kev nyab xeeb - ntsuas tus contactor, cov no yog qhov yuav tsum tau nres thaum muaj xwm txheej ceev, cov ntaub thaiv teeb pom kev zoo, kev tiv thaiv kev cuam tshuam, thiab ob- tes tswj. Lawv yuav tsum ua kom tau raws li ISO 13849-1 ntawm PL d lossis PL e, nrog rau kev quab yuam- coj kev sib cuag thiab kev saib xyuas dual-channel ua hauv.
Ntawm 40-I / O vaj huam sib luag kuv tau teev tseg hauv 2025, ua raws li txoj cai no coj cov ntawv hloov pauv hloov pauv los ntawm peb lub xyoo mus rau xoom. Thiab nws tsuas yog ntxiv qee yam xws li kwv yees li $ 180[9]hauv cov khoom siv ntxiv. Qhov kev nqis peev ntawd tau them rov qab rau hauv plaub lub hlis.
Vaj huam sib luag tsim daim ntawv txheeb xyuas, txuag qhov no ua ntej koj tsim tom ntej:
Sau tawm txhua qhov tso zis: hom kev thauj khoom nws yog dab tsi, qhov voltage, tam sim no, thiab ntau npaum li cas nws hloov.
Chij ib qho load rub dhau 0.5 A lossis ib qho AC load, cov neeg xav tau kev sib cuam tshuam.
Chij txhua lub neej- kev nyab xeeb muaj nuj nqi, uas xav tau kev nyab xeeb kom raug, xaim tag nrho sab nraum PLC txoj kev logic.
Ntxiv flyback diodes rau DC lossis RC snubbers rau AC ntawm txhua lub kauj.
Xa ib lub koom haum ib txwm- kaw kev sib cuag los ntawm txhua qhov tseem ceeb relay rov qab mus rau PLC cov tswv yim kom koj tuaj yeem saib xyuas nws rau kev kuaj mob.
Sau npe rau txhua lub qhov hluav taws xob relay nrog lub load nws tswj, qhov voltage, thiab tus lej seem.
Sau cov khoom tawm, kaw nws hauv lub qhov rooj vaj huam sib luag, thiab tus kws tshaj lij tom ntej uas qhib lub txee yuav ua tsaug rau koj.
Cov ntaub ntawv
[1]siron-group.com/What-Yog-A-Relay-hauv-A-PLC-id46806385.html
[2]control.com/textbook/relay-tswj-systems/interposing-relays/
[3]realpars.com/blog/advantages-plcs-over-relay-systems
[4]tw-rstpower.com/info/what-yog-tswj-relay-in-plc--91521116.html
[5]motioncontroltips.com/choosing-nruab nrab-los yog-combining-relays-thiab-plcs/
[6]control.com
[7] realpars.com
[8] motioncontroltips.com
[9] automationcommunity.com
[10]automationcommunity.com/difference-nruab nrab-plc-thiab-relay/
[11]automationelectric.com/plc-vs-relay-raws li- tswj-systems- ua- tus- txoj cai-ch...