INDUCTIVE LOADS

High voltage transients may occur switching inductive loads.

Through the internal contacts these transients may introduce disturbances which can affect the performance of the instrument.

For the OUT 2 and OUT 3, the internal protection (varistor) assures a correct protection up to 0.5 A of inductive component.

The same problem may occur when a switch is used in series with the internal contacts as shown in Fig. 9.

LINEAR OUTPUT

This instrument is equipped with one linear output (OUT 1) programmable as:

-main output (heating or cooling)

-secondary output (cooling)

-analog retransmission of the measured value

-analog retransmission of the operative set point.

 

 

 

+

 

+

 

 

 

6

 

 

mA

 

 

 

 

 

 

 

 

OUT 1

_

 

 

 

 

 

 

20

 

 

 

 

_

 

 

 

 

 

 

 

 

 

 

7

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

R

LOAD

POWER

LINE

Fig. 10 mA OUTPUT WIRING

Fig. 9 EXTERNAL SWITCH IN SERIES WITH THE INTERNAL CONTACT

In this case it is recommended to install an additional RC network across the external contact as show in Fig. 9

The value of capacitor (C) and resistor (R) are shown in the following table.

LOAD

C

R

P.

OPERATING

(mA)

(mF)

(W)

(W)

VOLTAGE

 

 

 

 

 

 

<40

mA

0.047

100

1/2

260 V AC

<150 mA

0.1

22

2

260 V AC

<0.5

A

0.33

47

2

260 V AC

 

 

 

 

 

 

The cable involved in relay output wiring must be as far away as possible from input or communica- tion cables.

6

It is an isolated analog output. Maximum load: 500 W.

1604-7-1-AB.p65

6

5/16/00, 10:50 AM

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Chromalox 1604-7 user manual Inductive Loads, Linear Output, Load Operating Voltage