61F

Floatless level controller Bé ®iÒu khiÓn kiÓm tra møc

Automatic Water Supply and Drainage

ControlTù ®éng ®iÒu khiÓn cÊp tho¸t níc

Ideal for level control of any conductive

liquid

Lý tëng cho ®iÒu khiÓn møc níc víi

bÊt kú chÊt láng dÉn ®iÖn nµo

Both general-purpose and panel-use

models available

Cã c¸c lo¹i th«ng dông vµ lo¹i g¾n

trªn b¶ng Panen

Incorporates an arrester for surge and

induced lightning protection

Cã bé chèng xung vµ chèng sÐt c¶m

øng

Wide range of models:Long-distance, high-

and low-sensitivity, two-wire, etc.

Cã nhiÒu lo¹i lùa chän: Lo¹i truyÒn xa,

lo¹i ®é nh¹y cao vµ thÊp

LED indicator for quick operation check§Ìn Led gióp kiÓm tra ho¹t ®éng

nhanh

Conforms to EMC/IEC standards Tu©n theo c¸c tiªu chuÈn EMC/IEC

UL/CSA approved §· ®îc UL/CSA duyÖt

Operating Principle Nguyªn lý ho¹t ®éng

Unlike ordinary level switches that use a

float for level detection, the 61F Floatless

Level Controller uses electrodes to

electrically detect the liquid level. The

following figures illustrate this simple

operating

principle.

Kh«ng gièng nh c¸c c«ng t¾c møc níc

th«ng thêng dïng phao næi. §é ®iÒu

khiÓn kiÓm tra møc 61F sö dông

®iÖn cùc ®Ó nhËn biÕt møc chÊt

láng dÉn ®iÖn. C¸c h×nh ¶nh díi

®©y minh ho¹ nguyªn lý ho¹t ®éng

®¬n gi¶n nµy.

When electrode E1 is not in contact with

the conductive liquid, the electrical circuit

is open, and no current flows between

electrodes E1 and E3.

Khi ®iÖn cùc E1 kh«ng tiÕp xóc víi

chÊt láng dÉn ®iÖn, m¹ch ®iÖ hë, vµ

kh«ng cã dßng ®iÖn nµo gi÷a ®iÖn

cùc E1 vµ E3.

Consequently, relay X does not operate.

Relay X’s NC contacts (normally closed, b

in the figure) remain closed. However,

when liquid is supplied to the tank, so that

the liquid contacts or immerses E1, the

circuit closes. Relay X operates, and

electrical devices connected to the NO

Do ®ã, R¬le X kh«ng ho¹t ®éng.

TiÕp ®iÓm thêng ®ãng NC (normally

closed) cña r¬le X vÉn ®ãng (trong

h×nh b). Tuy nhiªn, khi chÊt láng

ch¶y vµo bÓ, lµm cho chÊt láng tiÕp

xóc víi ®iÖn cùc E1 hoÆc lµm ngËp

®iÖn cùc E1, m¹ch ®iÖn ®ãng l¹i. R¬

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61F

(normally open, a in the figure) contacts of

the relay begin operation.

le X ho¹t ®éng, vµ c¸c thiÕt bÞ ®iÖn

nèi víi c¸c tiÕp ®iÓm NO cña r¬le

b¾t ®Çu ho¹t ®éng.

A pump is usually connected to a

contactor, which in turn is connected to

the Controller contact outputs. The Level

Controller would automatically operate the

pump, to control the liquid level in the

tank.

B¬m thêng ®îc nèi th«ng qua 1 c«ng

t¾c t¬, tíi c¸c ®Çu ra tiÕp ®iÓm cña

bé ®iÒu khiÓn. Bé ®iÒu khiÓn møc

tù ®éng ch¹y b¬m ®Ó ®iÒu khiÓn

møc chÊt láng trong bÓ.

However, in practice, with only two

electrodes, ripples on the surface of the

liquid cause the Controller to jump and

start, shortening pump (and other

equipment) life. This problem can be

solved by adding another electrode to

form a self-holding circuit. The additional

electrode, E2, is connected in parallel with

E1, as shown below

Tuy nhiªn, trong thùc tÕ, chØ víi 2

®iÖn cùc, gîn sãng ë trªn bÒ mÆt

cña chÊt láng lµm cho bé ®iÒu khiÓn

khëi ®éng bÊt thêng, gi¶m tuæi thä

cña m¸y b¬m (vµ c¸c thiÕt bÞ kh¸c).

Gi¶i quyÕt vÊn ®Ò nµy b»ng c¸ch

thªm 1 ®iÖn cùc kh¸c ®Ó t¹o m¹ch tù

gi÷. §iÖn cùc thªm vµo, E2 ®îc nèi

song song víi E1, nh h×nh díi ®©y.

As shown in the above figure, when the

holding circuit relay is energized, contact

a2, its NO contact, is closed. The electrical

circuit made through the liquid and the

electrodes is then retained by E2 and E3,

even when the liquid level falls below E1,

as long as contact a2 is closed.

Nh ®· chØ ra trong h×nh trªn, khi

r¬le m¹ch tù gi÷ cã ®iÖn, tiÕp ®iÓm

thêng më NO cña contactor a2 ®îc

®ãng l¹i. M¹ch ®iÖn ®îc t¹o thµnh

qua chÊt láng vµ c¸c ®iÖn cùc vµ ®îc

duy tr× bëi E2 vµ E3, thËm chÝ khi

møc chÊt láng xuèng díi E1 , tiÕp

®iÓm a2 vÉn ®ãng.

When the liquid level falls below E2, the

circuit made through the electrode circuit

opens, which de energizes relay X, thus

closing the NC contact of X.

Khi møc níc xuèng díi møc E2, m¹ch

®iÖn t¹o ra qua ®iÖn cùc hë, r¬le X

mÊt ®iÖn, v× thÕ tiÕp ®iÓm thêng

®ãng cña r¬le X ®ãng l¹i

Operating as simply as it does, possible

applications of the Floatless Level

Controller are virtually endless. Not only

liquid level control is possible, but such

applications as leakage detection, object

size discrimination, and many other

Ho¹t ®éng ®¬n gi¶n nh vËy, nhng

c¸c øng dông cña bé ®iÒu khiÓn møc

rÊt phong phó. Bé 61F kh«ng chØ cã

thÓ ®iÒu khiÓn møc chÊt láng, mµ

cßn dïng trong c¸c øng dông nh ph¸t

hiÖn rß rØ, ph©n biÖt kÝch cì vËt - 2 -

61Fproblems may be solved by one of the

reliable 61F Floatless Level Controllers.thÓ, vµ nhiÒu bµi to¸n kh¸c

Model Selection Lùa chän chÕ ®é

Basic Configuration of 61F Conductive

Level Controller

CÊu h×nh c¬ b¶n cña bé ®iÒu khiÓn

møc chÊt láng dÉn ®iÖn 61F

To use a 61F Conductive Level Controller,

the 61F itself, Electrode Holders, and

Electrodes are required.

§Ó sö dông 1 bé ®iÒu khiÓn 61F, cÇn

thiÕt ph¶i cã bé 61F, c¸c bé gi÷ ®iÖn

cùc, vµ c¸c ®iÖn cùc

Select from the capability, function, and

size to suit the application.

Chän theo kh¶ n¨ng, chøc n¨ng, vµ

kÝch cì ®Ó phï hîp víi øng dông

Refer to the following Controller selection

guidelines.

Xem híng dÉn lùa chän bé ®iÒu

khiÓn díi ®©y.

Floatless Level Controller

Floatless CFloatless Level Controller

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61F

Floatless Level Controllerontroller

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