ESD 92 Series User manual

Digital Temperature Controller
ESD 92 series
1. Introduction
The Inside Stuff
Version - 12
Date - 25 April 08
Temperature Indicators and Controllers
play an important part in any process
industry. Quick and accurate measurement
and control of process temperature will
improve the final product quality, reliability
and reduce rejection. Temperature
indication and control is therefore one of the
prime considerations in any process
industry.
The ESD 92 series is a On / Off type Digital
Temperature Controller designed for fast
and accurate measurement and control. The
instrument is designed using highly reliable
electronic components. Process
temperature is displayed directly in digits,
giving better resolution compared to analog
indicators.
The ESD 92 series accepts all types of
Thermocouples, Pt - 100, 0 to 20 mA, 4 - 20
mAas well as 0-2/5/10 V DC as input . Wide
ranges of measurements are available.
The instrument is immune to mechanical
vibrations. Even the mounting position will
not affect the measurement accuracy. The
large bright red LED seven segment display
allows long distance readability. Use of
highly reliable electronic components with
low temperature coefficient ensure long and
trouble free service. The instrument is
tested for its performance under various
climatic conditions.
1. Introduction
2. Principle of
Operation
3. Features
4. Specifications
5. Block Diagram
6. Schematic
7. Installation
8. Calibration
9. Look-up Table
10. Fault Diagnosis
11. As you unpack
12. Warranty
Certificate
13. Ordering
Information
14. Health Tips
15. Definitions

2. Principle of Operation
3. Features
The ESD 92 series is based on the principle of a high input impedance
amplifier feeding a comparator followed by a relay and an analog to
digital convertor. The input signal generated by the transducer is fed to
a sensor compensation circuit, where automatic ambient
compensation in case of thermocouple & lead resistance
compensation in case of Pt-100 is achieved.
Duly compensated signal is fed to a signal conditioning amplifier,
output of which is given to digital display as well as to a comparator.
This comparator compares the process value with the desired value
(Set point). Output of the comparator is given to the relay which
switches ON or OFF depending upon the process value as compared to
the setpoint.
Linearisation of the input signal from the transducer is done by
hardware in the input circuit. This gives a standardized signal to the
analog to digital convertor which drives the LED display, indicating
the temperature directly.
Proven field performance
Highly compact
Dust and vermin proof enclosure with epoxy powder coating
LED display gives better long distance readability
Feather touch Push buttons
Fast response
Available in different DIN standard cutouts
Designed for Thermocouples, RTD, mA, mV input
Fail safe relay logic
Maximum MTBF and minimum MTTR

Model : ESD - 9213 / ESD - 9223
Control action : On / Off
Ranges : Refer Ordering Information chart
Input : Thermocouples / Pt - 100 (3 wire sys) / 4 - 20 mA
Indication accuracy : +/- 0.5 % of FS +/- 1 digit
4. Specifications
ooo o
Least count : 0.1 C upto 200 C, 1 C above 200 C
Accuracy deviation
oo
a) Temperature change : +/- 0.01 % / C , reference at 25 C
b) Supply Variation : +/- 0.005 % /V from rated supply
Set point : One / Two (through ten turns potentiometer)
Set point Read : By pressing respective self release switch on front panel
Set point Read & Adjust : By pressing self release switch and simultaneously
(on front panel) turning corresponding set potentiometer
Outputs : One set of Relay change over contact 5 Amp resistive
at 230 V AC per setpoint
Relay logic : 1. Actual temp. < set point - Relay ON for
Heating application (Factory set)
2. Actual temp. > set point - Relay ON for
Cooling application (On demand)
Relay ON indication : By Red LED per setpoint
Control Sensitivity : 0.25% of FS
Display : 3 & 1/2 digit 7 segment 12.5 mm Red LED
Power supply : 230 V AC, +/- 10 % , 50 Hz
o
Ambient Temp. range : 0 to 55 C
o
Amb. Temp. Compensation: Built in upto 55 C only for thermocouple input.
Sensor break indication : Up scale [i___] (Down scale on demand )
Sensor break protection : Relay ‘Off’ (Relay ‘On’ by demand)
Relative Humidity : 90 % Non-condensing
Power consumption : 6 VA
Input impedance : > 10 Mohms, (only for thermocouple input )
Weight : 800 grams approximately
Mounting : Flush Panel
2
Termination : PUT 2.5 mm / PBT
Dimensions (mm) Panel Cutout Front Facia Depth
92 x 92 (+1,-0) 96 x 96 80

1. Transducer : This block consists of either a Thermocouple, Pt- 100 (RTD) or
a 4 - 20 mA current signal. It senses the temperature and sends a signal to the
sensor compensation circuit.
2. Signal conditioner : consists of a bridge generating mV signal corresponding
to the ambient temperature. In case of thermocouple input this is added to input
mV signal for automatic ambient temperature compensation. In case of Pt-100
input, it gives constant current for Pt-100 excitation and provides 3 wire system
for lead wire compensation.
3. Amplifier : reads the signal from the sensor and calculates the temperature. It
consists of a bridge and an amplifier. The signal from the sensor causes an
unbalance in the bridge. This unbalance is proportional to the temperature being
measured. The output of the bridge is amplified and calibrated suitably. The
amplifier o/p is fed to the display circuit and the comparator.
4. ADC & Display : consists of an analog to digital convertor (ADC), a digital
voltmeter and 4 seven segment LED displays. The ADC converts the analog
output of the amplifier to a digital signal which is read by the digital voltmeter
and displayed on the seven segment displays, directly in terms of process
parameter.
5. Setpoints : consists of ten turn highly stable potentiometer excited by
precision regulated power supply for setting desired set values.
6. Comparator : compares the output of the amplifier (process value), with the
set point set by the user. Depending on whether the process value is greater than
or less than the set point the comparator output is either -ve or +ve. For ‘n’ set
points we have ‘n’comparators.
7. Relay : The relay switches ON or OFF depending on comparator output. For
‘n’set points we have ‘n’relays.
5. Block Diagram
Signal
Conditioner Amplifier ADC &
Display
Comparator-1
Comparator-2
Relay -1
Relay -2
Setpoint -1
Setpoint -2
Field
Field
Control
through
Contactors
Transducer
&
Transmitter

6.1 Schematic & Connection Diagram for ESD 9213
E N P
NC PNO
RL1
C
RC1
1 2 3 4 5 6 7 8 9
Pt 100
+
-
TC
SUPPLY
VOLTAGE
Pt-100 (3 WIRE RTD)
TC - THERMOCOUPLE
2II
Display board
ESD - 9123DPM-R3
CONTROL SET PRESS
DISPLAY
7 Pin connector
Secondary
Sensitivity Span
Zero
Transformer
ESD - 189
Relay
Sensor
Primary
Backcard
ESD - 9123BK-R3
E N P NC PNO R G B
Relay1
Mother board
ESD - 9213MB4
TB
User Terminals
1 2 3 4 5 6 7 8 9
CONTROL - Red LED's for Relay
Status
SET - Potentiomenters for
setpoint adjust
PRESS - Press Switches to
read set values
DISPLAY - 12.5 mm 7 segment
RED LED
VSEN - ‘Sensitivity’
adjust Potentiometers
SPAN -‘Span’ adjust
Potentiometer
ZERO -‘Zero’ adjust
Potentiometer
IC1 - Amplifier
IC2 - Comparator
RL - 12 V DC Relays
TB -PBT Terminal board

6.2 Schematic & Connection Diagram for ESD 9223
CONTROL - Red LED's for Relay
Status
SET - Potentiomenters for
setpoint adjust
PRESS - Press Switches to
read set values
DISPLAY - 12.5 mm 7 segment
RED LED
VSEN1/ VSEN2 - ‘Sensitivity’
adjust Potentiometers
SPAN -‘Span’ adjust
Potentiometer
ZERO -‘Zero’ adjust
Potentiometer
IC1 - Amplifier
IC2 - Comparator
RL1, RL 2 - 12 V DC Relays
Pt-100 (3 WIRE RTD)
TC - THERMOCOUPLE
EN P
NC PNO NC PNO
CC
RR
C1 C2
1 2 3 4 5 6 7 8 9
SUPPLY
VOLTAGE
10 11 12
Pt 100
+
TC
Relay 1 Relay 2
2ii
Display board
ESD - 9223DPM-R1
CONTROL SET PRESS
DISPLAY
10 Pin connector
Secondary
Sensitivity
Span
Zero
Transformer
ESD - 189
Relay2
Relay
Sensor
Primary
Backcard
ESD - 9223BK-R2
E N P NC PNO R G B
Relay1
NC PNO
Mother board
ESD - 9223MB-R2
TB -PBT Terminal board
TB
User Terminals
1 2 3 4 5 6 7 8 9 10 11 12

7. Installation Procedure
$Also observe Instrumentation Health Tips chapter 14
105 mm
CONTROL
ESD - 9223
TEMPERATURE CONTROLLER
PRESS
I
II
542
E L E C T R O N I C S
SYSTEMS AND DEVICES
C
The instrument should be mounted in a place where it is clearly visible and
accessible.
1. Insert the instrument in the cutout and fix it using the bracket pair.
2. Depending on the type of instrument make connections as shown in
Connection diagram ( Chapter 6 ).
3. In case of Pt-100 sensor Red wire is to connected to the terminal indicated
with a Box.
4. In case of thermocouple input : (a) for ESD-9213 terminal no.8 has no
connection. (b) for ESD-9223 terminal no. 11 has no connection.
5. Use correct compensating cables for thermocouple type instruments.
6. Ensure proper earthing to the instrument.
7. Output loads connected through the relay change over contact should be
less than the maximum specified value.
8. Connect a series combination of 0.1 F /600 V non polar capacitor & 2 20
1/2 Wresistor across phase & neutral.
9. For setting set values as per your requirement, press the push button and
rotate respective potentiometer with proper size screw driver.
10. If factory set control sensitivity (0.25% of FS) is not suitable for your
application, then adjust it by the potentiometer marked SENSITIVITY
(inside the instrument).
i) If relay chattering is observed, reduce the sensitivity by turning the
potentiometer Counter Clock Wise (CCW) .
ii) If over-shoots and under-shoots are observed increase the sensitivity by
turning the potentiometer Clock Wise (CW) .

8. Calibration Procedure
Warning: Procedure to be carried out strictly by technical persons.
MFollow instructions given in this manual.
The instrument is calibrated at the factory using accurate calibrating
equipment traceable to international standards. No recalibration should
be required in normal course, however if the instrument requires
recalibration, follow the procedure given below:
i. Remove the cover of the instrument, by removing the fixing
screws on the back side of the instrument.
ii. Switch on the supply and allow 5 min. to achieve thermal stability.
iii. For uniform error distribution calibration points should be at 20%
of Full Scale (FS) for ZERO calibration and at 80% of FS for SPAN
o
calibration. i.e. If the range is 0 to 1000 C, the ZERO calibration
o
should be done at 200 C (20% of FS) and SPAN calibration should be
o
done at 800 C (80% of FS).Depending on the type of input proceed as
follows :
8.1) Thermocouple input
1. Remove the thermocouple from its terminals and connect a stable
mV source in its place with proper polarity.
2. Feed ambient compensated mV corresponding to 20 % of FS.
The display should show corresponding temperature. If the
displayed temperature is incorrect turn the potentiometer marked
'ZERO' to display correct reading (CW to increase & CCW to
decrease).
o
eg.: Cr-Al thermocouple - Ambient compensated mV for 200 C
oo
at ambient temp 30 C will be mV corresponding to 200 C
o
(8.137mV) minus mV corresp to 30 C (1.203 mV) = 6.934 mV

3. Feed ambient compensated mV corresponding to 80 % of FS.
The display should show corresponding temperature. If the
displayed temperature is incorrect turn the potentiometer marked
'SPAN' to display correct reading (CW to increase & CCW to
decrease).
o
eg.: Cr - Al thermocouple - Ambient compensated mV for 800 C
oo
at ambient temp 30 C will be mV corresp. to 800 C (33.277 mV)
o
minus mV corresponding to 30 C (1.203 mV) = 32.074 mV
Repeat steps 2 and 3 to get zero error at both calibration points.
8.2) Pt - 100 input ( 3 wire system)
1. Remove the Pt - 100 from its terminals and connect a resistance
decade box with 3 wire system in its place.
2. Feed resistance corresponding to 20 % value of FS (eg.resistance
oo
corresponding to 20 C for 0 to 100 C range) The display should
show corresponding temperature. If the displayed temperature is
incorrect turn the potentiometer marked 'ZERO' to display correct
reading. (CW to increase and CCWto decrease)
3. Feed resistance corresponding to 80 % value of FS (eg. resistance
oo
corresponding to 80 C for 0 - 100 C range). The display should
show corresponding temperature. If the displayed temperature is
incorrect adjust the potentiometer marked 'SPAN' to display
correct reading. (CW to increase and CCWto decrease).
Repeat steps 2 and 3 to get zero error at both calibration points.
Check the calibration of the instruments every six months.
In case of error recalibrate using certified calibrators only.
6

Temp. in
Deg. C
Output in mV (Reference junction at 0 Degree Celcius)
Fe - Ko
( J )
Cr - Al
( K )
Pt-Pt,13% Rh
( R )
Pt-Pt,10% Rh
( S )
oo
KC= 273.15 + oo
F C= (1.8 x ) + 32
Charts for higher resolution on demand
Pt-100
resis.
in ohms
-100 60.25 -4.63 -3.55 - -
-50 80.31 -2.43 -1.89 - -
-25 90.13 -1.24 -0.37 - -
0 100.00 0.00 0.00 0.00 0.00
10 103.90 0.51 0.40 0.11 0.05
20 107.79 1.02 0.80 0.17 0.11
22 108.57 1.12 0.88 0.12 0.13
24 109.35 1.23 0.96 0.14 0.14
26 110.12 1.39 1.04 0.15 0.15
28 110.90 1.43 1.12 0.16 0.16
30 111.67 1.54 1.20 0.23 0.17
32 112.45 1.64 1.29 0.18 0.19
34 113.22 1.75 1.37 0.20 0.20
36 113.99 1.85 1.47 0.21 0.21
38 114.77 2.00 1.53 0.22 0.22
40 115.54 2.06 1.61 0.30 0.24
50 119.40 2.59 2.02 0.36 0.30
60 123.24 3.12 2.44 0.43 0.37
80 130.89 4.19 3.27 0.57 0.50
100 138.50 5.27 4.10 0.72 0.65
120 146.06 6.36 4.92 0.88 0.80
140 153.58 7.46 5.73 1.04 0.95
160 161.04 8.56 6.54 1.21 1.11
180 168.46 9.67 7.34 1.38 1.27
200 175.84 10.78 8.14 1.56 1.44
250 194.07 13.55 10.15 2.02 1.87
300 212.02 16.33 12.21 2.50 2.32
350 229.67 19.09 14.29 3.00 2.79
400 247.04 21.85 16.40 3.51 3.26
500 280.90 27.39 20.64 4.58 4.23
600 313.59 33.10 24.90 5.70 5.24
700 345.13 39.13 29.13 6.86 6.27
800 - - 33.28 8.07 7.35
900 - - 37.33 9.20 8.45
1400 - - - 16.04 14.37
1600 - - - 18.84 16.77
1000 - - 41.27 10.50 9.59
1200 - - 48.83 13.22 11.95
9. Look-up Table Temperature vs Sensor output