Omron K2CU-F10A-CGS, K2CU-F80A-CGS, K2CU-F20A-CGS, K2CU-F40A-CGS, K2CU-F10A-DGS User Manual

1

Heater Element Burnout Detector

K2CU

Accurate Detection of Heater Element Burnout Regardless of Heater Capacities

Accurately detects a burned heater element or elements incorporated by a molding machine or packing machine and outputs an alarm signal.

Precisely singles out the burned element even if one heater element among several heater elements has been burned out.

Applicable to small- to large-capacity heater elements.

All K2CU-F large-capacity, built-in current transformer models work with both single-phase and three-phase heaters.

Voltage fluctuation compensation function eliminates false alarms due to variations in the supply voltage.

Ordering Information

K2CU-FjjA-jGS Model with Gate Input Terminals

Control

supply voltage

Operating current

4 to 10 A 8 to 20 A

16 to 40 A 32 to 80 A

100 V

AC W

ith voltage fluctuation

K2CU-F10A-CGS K2CU-F20A-CGS K2CU-F40A-CGS K2CU-F80A-CGS

1

10 V

AC compensation K2CU-F10A-DGS K2CU-F20A-DGS K2CU-F40A-DGS K2CU-F80A-DGS

200 V

AC K2CU-F10A-EGS K2CU-F20A-EGS K2CU-F40A-EGS K2CU-F80A-EGS

220 V

AC K2CU-F10A-FGS K2CU-F20A-FGS K2CU-F40A-FGS K2CU-F80A-FGS

K2CU-F Large-capacity, Built-in Current Transformer Models

Control

supply voltage

Operating current

4 to 10 A 8 to 20 A

16 to 40 A 32 to 80 A

100 V

AC W

ith voltage fluctuation

K2CU-F10A-C K2CU-F20A-C K2CU-F40A-C K2CU-F80A-C

1

10 V

AC compensation K2CU-F10A-D K2CU-F20A-D K2CU-F40A-D K2CU-F80A-D

200 V

AC K2CU-F10A-E K2CU-F20A-E K2CU-F40A-E K2CU-F80A-E

220 V

AC K2CU-F10A-F K2CU-F20A-F K2CU-F40A-F K2CU-F80A-F

K2CU-P Small-capacity, Plug-in Models

Control

supply voltage

Operating current

0.25 to 0.5 A

0.5 to 1 A

1 to 2 A 2 to 4 A

100/ 200 V

AC

W

ith voltage fluctuation

compensation

K2CU-P0.5A-A K2CU-P1A-A K2CU-P2A-A K2CU-P4A-A

W

ithout voltage

fluctuation compensation

--- K2CU-P1-A K2CU-P2-A K2CU-P4-A

110/ 220 V

AC

W

ith voltage fluctuation

compensation

K2CU-P0.5A-B K2CU-P1A-B K2CU-P2A-B K2CU-P4A-B

W

ithout voltage

fluctuation compensation

--- K2CU-P1-B K2CU-P2-B K2CU-P4-B

K2CU

2

Specifications

Ratings

Item K2CU-F K2CU-P

Control

supply voltage

100, 1

10, 200, 220 V

AC

100/200, 1

10/220 V

AC

Rated frequency

50/60 Hz

Carry current

1.25 times as large as each model’

s

maximum operating current

2.5 A for K2CU-P0.5A-A/-B; 5 A

Operating voltage range

85% to 1

10% of control supply voltage

V

oltage fluctuation compensation

range

85% to 1

10% of control supply voltage

85% to 1

10% of control supply voltage (applicable only on models with voltage fluctuation compensation)

Operating current

4 to 10 A, 8 to 20 A, 16 to 40 A, 32 to 80 A (continuously variable)

0.25 to 0.5 A, 0.5 to 1 A, 1 to 2 A, 2 to 4 A (continuously variable)

Releasing current

105% max. of operating current

1

10% max. of operating current

Operate time

0.5 s max. (when current changes from 150% to 0%)

Gate input voltage range (for models with gate input terminals)

5 to 30 VDC

---

Control output

2 A at 220 V

AC, SPDT (cosφ

= 0.4)

Power consumption

Input: 0.5 V

A max.

Power supply: 5 V

A max.

Input: 1 V

A max.

Power supply: 4 V

A max.

Characteristics

Setting

accuracy

±

7% max.

Repeat accuracy

±

3% max.

Influence of temperature

±

10% max. (at 20

°C±30°C)

Influence of voltage

Models without voltage fluctuation compensation:

±

3% max. of the value measured at the control supply voltage, on condition that the voltage

fluctuation is 85% to 1

10% of the control supply voltage

Models with voltage fluctuation compensation:

±

5% max. of the logical value, on condition that the voltage fluctuation is 85% to 1

10% of the

control supply voltage. (see note)

Influence of frequency

±

3% max. (at ±5% of rated frequency)

Insulation resistance

10 MΩ min. (at 500 VDC) between electric circuits and mounting panel

Dielectric strength

2,000 V

AC, 50/60 Hz for 1 min between electric circuits and mounting panel

Overcurrent

20 times of max. set value of operating current for 2 s

V

ibration resistance

Destruction: 16.7 Hz, 1-mm double amplitude for 10 min each in X, Y

, and Z directions

Shock resistance

Destruction: 100 m/s2 (approx. 10G)

Ambient temperature

Operating: –10°C to 55°C (with no icing)

Ambient humidity

Operating: 45% to 85%

Weight

K2CU-F: approx. 390 g; K2CU-P: approx. 300 g

Note: The

logical value is an operating value within a range of 0.85 to 1.1 with a voltage fluctuation of 85% to 1

10%, based on the value at the

control

supply voltage measured as 1.

K2CU

3

Operation

K2CU-F A- GS

Series

When

power is supplied to the heater (when the SSR is ON), a cur

rent flows through the wires to the heater elements. At the same time, a voltage is imposed on the gate circuit and the K2CU-FjjAjGS begins monitoring the current flowing through the

heater wires.

The current flowing to the heater wires is detected by the detector sections through each Current Transformer (CT) incorporated by the K2CU-FjjA-jGS.

The

current signals transmitted by the two CT

s are sent to the cur

rent-voltage converters, smoothing circuits, and comparators as shown

in the diagram.

The

signal generated by the reference voltage generator is sent to

the

setting circuit to provide a reference value. The reference value is sent to the comparators. Each comparator compares its heater element

current input

and the reference value. If the input is lower

than the reference value, a signal is sent to the output circuit. There

are two

detector sections operating independently

. If either of

the

input signals from the CT

s is lower than the reference value, the

output

relay and alarm indicator will be activated.

The K2CU-FjjA-jGS incorporates a voltage fluctuation compensation

function which automatically corrects the reference value

if

the supply voltage fluctuates.

Currentvoltage converter

Smoothing circuit

Gate circuit

Setting circuit

Reference voltage generator

Power circuit

Currentvoltage converter

Smoothing circuit

BZ

Output circuit

Temperature controller

X CM1

a1

b1

S2S1G–G+

CT

1

CT

2

SSR DC

Heater elements

Power source

X/c

Output relay

Alarm indicator

Buzzer

To each circuit

Note: 1. The

dotted lines indicate the line conductors passing through the windows of the current transformers.

2.

The current flowing into the gate circuit (between G+ and G–) is as follows: Approximately 1.4 mA at 5 VDC Approximately 3.4 mA at 12 VDC Approximately 6.7 mA at 24 VDC

3

When using a K2CU which has the model number suf

fix ”GS” (a model that incorporates gate input

terminals), the control output of the temperature controller must be a voltage output type.

Comparator

K2CU

4

K2CU-F

Series

When

power is supplied to the heater (when the contactor

is ON), a current flows through the wires to the heater elements. At the same time,

a voltage is imposed on the power circuit of the K2CU-F

.

The current flowing to the heater wires is detected by the detector sections through each Current Transformer (CT) incorporated by the K2CU-F.

The

current signals transmitted by the two CT

s are sent to the cur

rent-voltage converters, smoothing circuits, and comparators as shown

in the diagram.

The

signal generated by the reference voltage generator is sent to

the

setting circuit to provide a reference value. The reference value is sent to the comparators. Each comparator compares its heater element

current input

and the reference value. If the input is lower

than the reference value, a signal is sent to the output circuit. There

are two

detector sections operating independently

. If either of

the

input signals from the CT

s is lower than the reference value, the

output

relay and alarm indicator will be activated.

The

K2CU-F incorporates a voltage

fluctuation compensation func

tion which automatically corrects the reference value if the supply voltage

fluctuates.

Currentvoltage converter

Smoothing circuit

Setting circuit

Reference voltage generator

Power circuit

Currentvoltage converter

Smoothing circuit

BZ

Output circuit

X CM1

a1

b1

S2S1

CT

1

CT

2

Heater elements

Power source

X/c

Output relay

Alarm indicator

Buzzer

To each circuit

Comparator

Note: The

dotted lines indicate the line conductors passing through the windows of the current transformers.

Contactor

K2CU-P

Series

The

K2CU-P operates basically in the same way as the K2CU-F

.

The comparator compares external current signals and the reference value and outputs the result of the comparison to the output circuit.

Currentvoltage converter

Smoothing circuit

Setting circuit

Power circuit

BZ

Output circuit

X

3

4

5

87

Comparator

Reference voltage generator

Heater elements

Power source

X/c

Output relay

Alarm indicator

To each circuit

Contactor

6

Buzzer

CT

1

2

200/220 V 100/110 V 0 V

K2CU

5

Setting of Operating Current

Use the potentiometer on the front panel to set the operating current.

Rotate

the knob to set the desired current value at which the

Heater

Burnout

Detector should operate. Do

not exceed the maximum and

minimum

positions.

The K2CU-F’s scale is divided into 12 graduations including subgraduations

and the K2CU-P’

s scale is divided into 5 graduations.

The

knobs of

the K2CU-F and K2CU-P as shown in the illustrations

are

set to 32 A and 0.7 A respectively

.

The

set operating current is defined as the mean value

of the heater current under normal operating conditions and the heater current under

a burnout or abnormal condition.

Set value =

Normal current + abnormal current

2

Knob

Red point (indicates the set value)

Heater Connection and Current

The

following table shows the dif

ferent connections possible. The formula under each illustration indicates the electrical current value of

the

heater

elements under normal and abnormal conditions.

Phase

Normal condition

Abnormal condition

Single phase

200 V

5 A

1 kW

200 V

0 A

Three phase

Delta network

200 V

8.7 A

1 kW

(5 A x )

3

7.5 A

3

2

(5 A x x )

3

5 A

8.7 A

5 A

1

3

(5 A x x )

3

Star network

200 V

2.9 A

1 kW

1

3

(5 A x )

2.5 A

3

2

(5 A x x )

1

3

2.5 A

3

2

(5 A x x )

1

3

V network

200 V

5 A

8.7 A

5 A

1 kW

(5 A x = 8.7 A)

3

(5A x 1/2)

2.5 A

5 A

(5A x 1)

Note: Values

in this table are correct when a 200 V

AC, 1 kW heater is used on a single-phase or three-phase current.

K2CU

6

Operation Check

K2CU-F A- GS

The

operation of the heater burnout detector can be easily

checked

as

follows:

In a Single-phase Circuit

Set

the operating current to be 0.6 to 0.55 times the heater current.

Close the SW2 with switch SW1 turned on. Confirm that the alarm indicator remains of

f.

Turn

of

f SW1 and confirm that the alarm indicator comes on, and that

the

output relay operates.

K2CU-F

S1

S2

G+

G–

Heater

SW

1

SSR

SW

2

In a Three-phase, Delta Network

Set the operating current to be 0.6 times the heater current. Close

the SW3 with switches SW1 and SW2 turned

on. Confirm that

the

alarm indicator remains of

f.

Turn

of

f SW2 and confirm that the alarm indicator comes on, and that

the

output relay operates.

Turn

on SW1 set the operating current to be 0.9 times the heater cur

rent, and confirm that the alarm indicator goes off and the output relay

releases.

Turn

of

f SW1 and confirm that the alarm indicator comes on, and that

the

output relay operates.

G+

G–

S1

S2

K2CU-F

Heater

SW

1

SSR

SW

3

SW

2

In a Three-phase, Star Network

Set the operating current to be 0.9 times the heater current. Close the SW2 with switch SW1 turned on. Confirm that the alarm

indicator remains of

f.

Turn

of

f SW1 and confirm that the alarm indicator comes on, and that

the

output relay operates.

G+

G–

S1

S2

K2CU-F

Heater

SW

1

SSR

SW

2

K2CU

7

In a Three-phase, V Network 1

Set

the operating current to be 0.3 to 0.35 times the heater current.

Close the SW2 with switch SW1 turned on. Confirm that the alarm indicator remains of

f.

Turn off SW1 and confirm that the alarm indicator comes on, and that

the output relay operates.

G+

G–

S1

S2

K2CU-F

Heater

SW

1

SSR

SW

2

In a Three-phase, V Network 2

Set

the operating current to be 0.6 times the heater current (of

the phase connected between terminals 1 and 2, or the one passed through

the window

of the window-type Current T

ransformer of the

heater

burnout detector).

Close the SW2 with switch SW1 turned on. Confirm that the alarm indicator remains of

f.

Turn off SW1 and confirm that the alarm indicator comes on, and that

the output relay operates.

G+

K2CU-F

Heater

SSR

SW

2

SW

1

G–

S1

S2

K2CU-F, K2CU-P

The

operation of the heater burnout detector can be easily

checked

as

follows:

In a Single-phase Circuit

Set

the operating current to be 0.55 to 0.6 times the heater current.

Close the contactor with switch SW1 turned on. Confirm that the alarm

indicator remains of

f.

Turn

of

f SW1 and confirm that the alarm indicator comes on, and that

the

output relay operates.

K2CU-F

S1

S2

Heater

SW

1

2

K2CU-P

Heater

SW

1

Contactor

K2CU

8

In a Three-phase, Delta Network

Set the operating current to be 0.6 times the heater current. Close

the contactor with switches SW1 and SW2 turned on. Confirm

that

the alarm indicator remains of

f.

Turn

of

f SW2 and confirm that the alarm indicator comes on, and that

the

output relay operates.

Turn

on SW1 set the operating current to be 0.9 times the heater cur

rent, and confirm that the alarm indicator goes off and the output relay

releases.

Turn

of

f SW1 and confirm that the alarm indicator comes on, and that

the

output relay operates.

S1

S2

K2CU-F

Heater

SW

2

SW

1

Contactor

In a Three-phase, Star Network

Set the operating current to be 0.9 times the heater current. Close the contactor with switch SW1 turned on. Confirm that the

alarm

indicator remains of

f.

Turn

of

f SW1 and confirm that the alarm indicator comes on, and that

the

output relay operates.

Heater

S1

S2

K2CU-F

SW

1

Contactor

In a Three-phase, V Network 1

Set

the operating current to be 0.3 to 0.35 times the heater current.

Close the contactor with switch SW1 turned on. Confirm that the alarm

indicator remains of

f.

Turn off SW1 and confirm that the alarm indicator comes on, and that

the output relay operates.

S1

S2

Heater

K2CU-F

SW

1

Contactor

In a Three-phase, V Network 2

Set

the operating current to be 0.6 times the heater current (of

the phase connected between terminals 1 and 2, or the one passed through

the window

of the window-type Current T

ransformer of the

heater

burnout detector).

Close the contactor with switch SW1 turned on. Confirm that the alarm

indicator remains of

f.

Turn off SW1 and confirm that the alarm indicator comes on, and that

the output relay operates.

SW

1

Contactor

1

2

K2CU-P

Heater

K2CU-P

K2CU

9

S1

S2

Heater

K2CU-F

SW

1

Contactor

K2CU-F

Test Circuit

To

check the operation in detail, use the following circuit.

S1

S2

b1

CM1

a1

Slidac

K2CU-F

SW

1

R

Slidac

Switch

R

1

2

7

8

6

5

4

3

K2CU-P

Switch

The dotted lines indicate the line conductor passing through the round window of the current transformer.

Note: Determine

the value of R according to the specifications of the K2CU to be used. The dotted line indicates the connection at a supply voltage of 100 or 1

10 V

AC.

K2CU-F K2CU-P

Dimensions

Note:

All units are in millimeters unless otherwise indicated.

K2CU-P

Connecting Socket

K2CU-P

8PFA1

108

89

7

8.5

60

7291

3.5

5

K2CU

10

K2CU-F

111

60

6

20

33

95

108

Eight,

M3.5 terminal screws

Two, 20-dia. holes

6-dia. mounting hole

Alarm indicator

Potentiometer knob

102 90

Mounting

Holes

6.5

mm max.

102

Two, 6-dia. or M5 mounting holes

6.5 mm max.

Note: 1. Install

the K2CU-F on a flat surface.

2.

When solderless terminal lugs are desired, use ones having an outer diameter of 6.5 mm maximum.

Installation

External Connections

K2CU-F A- GS

Single-phase

Heater

Three-phase Heater

G+

G–

S1

S2

b1

CM1

a1

SSR

YBZL

Y/a

Heater

K2CU-F

G+

G–

S1

S2

b1

CM1

a1

YBZL

SSR

Temperature sensor

Y/a

Heater

K2CU-F

Temperature controller

Power source

Control voltage

Temperature sensor

K2CU

11

K2CU-F

Single-phase

Heater

Three-phase Heater

S1

S2

YBZL

CM1

a1

Y/a

Heater

K2CU-F

Temperature controller

Power source

S1

S2

YBZL

b1

CM1

al

Y/a

Heater

K2CU-F

Temperature controller

Power source

Control contact

Contactor

Temperature sensor

Three-phase, V-connected Heater

W

ith External Current T

ransformer

S1

S2

b1

CM1

al

Heater

K2CU-F

S1

S2

b1

CM1

al

Heater

K2CU-F10A-j

Power source

CT

jA/SA

CT

jA/SA

Note:

Pass two out of the three line conductors through the current transformers of the heater burnout detector twice as shown.

K2CU

12

K2CU-P Small-capacity, Plug-in Models

Small-capacity

Heater

W

ith External Current T

ransformer

1

2

YBZL

7

8

6

5

4

3

Temperature sensor

Y/a

Heater

K2CU-P

Temperature controller

Power source

Control contact

7

8

1

2

YBZL

6

5

4

3

Temperature sensor

Y/a

Heater

K2CU-P

Power source

CT jA/5 A

Temperature controller

Control contact

Contactor

Note: 1. The

dotted lines which pass through the heater burnout detector indicate the line conductor

passing

through the round “window” of the window-type Current T

ransformer.

2. Y:

External relay for self-holding circuit

BZ:

Alarm buzzer

L:

Alarm indicator

3. To

use an 100 (1

10) V

AC control power supply with K2CU-P

, connect

it to terminal 7 instead

of

6.

Precautions

K2CU-F A- GS

Use

the K2CU-F

jjA-j

GS (with

gate input terminals) in combina

-

tion with a temperature controller that has PID

with feed-forward cir

cuitry to control the heater temperature, in which case, the heater element(s)

must be turned ON or OFF for 0.1 s or longer

.

K2CU-F

When

a single-phase heater is used, pass the two lines through the

openings of the heater burnout detector

. When a three-phase heat

er is used, pass two (phases) of the three lines through the

open

ings.

In either case, if only one line passes through, an alarm signal

will

always be produced.

With single-phase power supply

With three-phase power supply

Heater

Pass the lines through the

openings only once. If they are passed

more

than once, the actual operating current will be less than the set

current.

The lines can be passed in either direction.

To

use the heater burnout detector at a current less than the current

range

that can be set, the lines must be passed more than once. De

-

termine

the number of

times the lines should be passed by the fol

-

lowing

equation: (Operating current) x n = Current setting range where,

n: number of times the lines loop through the window All

K2CU-F models incorporate a voltage fluctuation compensation

function.

K2CU-P

The

K2CU-P can be used only in single-phase circuits.

Do

not pull out the K2CU-P from the socket when the K2CU-P is en

ergized. Especially when using it in combination with a Current Transformer commercially available, this practice causes the secondary

circuit of the transformer to open, which is very

dangerous.

K2CU

13

General

Refer to “

External Connections

” before using the K2CU with exter

-

nal CTs. When a temperature controller is used in combination with the

K2CU (except for the K2CU-FjjA-jGS), the heater element(s) must

be turned ON or OFF for 1

s or longer (although the heater ele

-

ment(s)

can be

turned ON for 0.5 s according to the specifications).

The

K2CU

cannot be used with a phase-control circuit, inverter cir

-

cuit,

frequency-count circuit, cycle-control unit, or a motor load.

Mounting

Securely mount the K2CU as horizontally as possible although there

is no particular limitation of mounting directions.

Connection

Solderless-type terminal must be connected to the terminals securely.

Wire

the terminals correctly by referring to the external connections.

The

terminals have no polarity

. Be sure to connect 100 (or 1

10) V to

the

100-V (or 1

10-V) terminals and 200 (or 220) V to the 200-V

(or

220-V)

terminals of the K2CU-P or the K2CU-P may malfunction.

The control power source for the K2CU (except for the K2CU-FjjA-jGS)

must

be supplied from the load side via a con

-

tactor. Be

sure

to impose a voltage between the 0-V terminal and 100-V (or

110-V)

terminal or the 0-V terminal and 200-V (or 220-V) terminal of

the K2CU-P

, otherwise the K2CU-P will not operate.

Operating Current Setting when Several Heaters are Used

The

following

table shows relative values of changes in the current

when

any one of several heaters

connected in parallel has burned

out.

The current value under normal condition is 1. Use this table as

a

guideline in determining the operating current.

Connection

n = 1 n = 2 n = 3 n = 4 n = 5

I

No.

of heater = n

0 0.5 0.67 0.75 0.8

Current

in burned-out phase

0 0.6 0.75 0.82 0.86

I

No.

of heater

per phase = n

Current

in other phases

0.87 0.92 0.95 0.96 0.97

Current in burned-out phase

0.58 0.77 0.84 0.88 0.91

I

No.

of heater

per phase = n

Current

in other phases

1 1 1 1 1

Note: 1.

This table shows the respective change rates in current when any one of several heaters connected in parallel has burned out.

2.

The current value under the normal condition is 1.

3. The

values in this table are logical values. Actually

, these values may vary slightly because of

influence of unbalanced loads (heat

-

ers).

It is therefore recommended to test the actual current values and the load condition before determining the operating current,

especially

when the current under the normal condition and that under an abnormal condition do not significantly dif

fer.

K2CU

14

OMRON Corporation

Measuring & Supervisory Controls Division 29th Fl., Crystal T

ower Bldg. 1–2–27, Shiromi, Chuo-ku, Osaka 540 Japan Phone: 06-949-6014 Fax: 06-949-6028

ALL DIMENSIONS SHOWN ARE IN MILLIMETERS.

To

convert millimeters into inches, multiply by 0.03937. T

o convert grams into ounces, multiply by 0.03527.

Cat. No. N39–E1–2 In the interest of product improvement, specifications are subject to change without notice.

Printed

in Japan

0393–1M (0393)