E309 technical manual

RDP Customer Document
Technical Manual
Transducer Indicator
TYPE E309
Doc. Ref CD1602S
This manual applies to units of mod status 8 ONWARDS
BS EN ISO 9001
Certificate No. FM13141
Affirmed by Declaration
of Conformity
USA & Canada
All other countries
RDP Electrosense Inc.
2216 Pottstown Pike
Pottstown, PA 19465
U.S.A.
Tel (610) 469-0850
Fax (610) 469-0852
E-mail info@rdpe.com
www.rdpe.com
RDP Electronics Ltd
Grove Street, Heath Town,
Wolverhampton, WV10 0PY
United Kingdom
Tel: +44 (0) 1902 457512
Fax: +44 (0) 1902 452000
E-mail: sales@rdpe.com
www.rdpe.com
INDEX
1.
INTRODUCTION .................................................................................................... 3
1.1 IMPORTANT SAFETY TEST INFORMATION. ....................................................... 3
1.2 Certificate of EMC Conformity ................................................................................ 4
2.
INSTALLATION INSTRUCTIONS........................................................................... 5
2.1
2.2
2.3
2.4
3.
EMC Requirements ................................................................................................. 5
Power Connections ................................................................................................. 5
Input and Output Signal Connections ..................................................................... 6
Transducer Connections (LVDT & Half bridge) ....................................................... 7
FRONT PANEL CONTROLS .................................................................................. 8
3.1
3.2
3.3
3.4
3.5
4.
Zero Potentiometer ................................................................................................. 8
Gain Potentiometer ................................................................................................. 8
Decimal Point Switch (DP) ...................................................................................... 8
Limits Switch ........................................................................................................... 8
Limit Level Potentiometers ...................................................................................... 8
REAR PANEL CONTROLS .................................................................................... 9
4.1
4.2
4.3
4.4
4.5
4.6
4.7
5.
Gain Range Switch & Selection .............................................................................. 9
Zero Input Switch .................................................................................................. 10
Zero Suppression Switch (Coarse Zero) ............................................................... 10
Output Gain Potentiometer ................................................................................... 11
Output 0mA/4mA Potentiometer ........................................................................... 11
Display Hold (Connector PL2)............................................................................... 11
Display Test (Connector PL2) ............................................................................... 11
INTERNAL CONTROLS ....................................................................................... 13
5.1
5.2
5.3
5.4
6.
Essential precautions prior to opening unit. .......................................................... 13
Supply Voltage ...................................................................................................... 13
Limits Mode........................................................................................................... 13
Frequency ............................................................................................................. 14
SETTING-UP PROCEDURE ................................................................................ 15
6.1
6.2
6.3
6.4
Factory-Calibrated Systems .................................................................................. 15
Bipolar calibration (e.g. ±5.000mm display) .......................................................... 15
Unipolar calibration (e.g. 0 to 10.000mm display) ................................................. 15
High Temperature LIN Transducers...................................................................... 15
7.
SPECIFICATION .................................................................................................. 16
8
APPLICATION NOTES ......................................................................................... 18
8.1 Electrical Interference Problems ........................................................................... 18
8.2 Bench/portable instrument .................................................................................... 19
9
WARRANTY AND SERVICE ................................................................................ 20
Table of Figures
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Connection for LVDT Transducers ...................................................................... 7
Connections for Differential Inductance (Half Bridge) Transducers .................... 7
Internal control locations ................................................................................... 12
Limits graphic with normal mode-link setting ..................................................... 13
2
1. INTRODUCTION
The E309 is an excitation/signal conditioning unit designed for use with LVDT, half-bridge
and similar a.c. transducers. A digital display provides indication, in engineering units, of
displacement, pressure, etc. together with analogue voltage and current outputs. Two
high-speed limit detectors provide volt-free relay outputs.
Features include:
a)
Simple setting-up via switches/potentiometers.
b)
Coarse gain and zero switches for long-term stability.
c)
Standard ±10v and 0/4-20mA analogue output.
d)
Bench or panel-mounting metal DIN case.
e)
Two independent limit detectors settable for Hi or Lo operation, with changeover
relay contacts and logic outputs.
f)
Display-hold and lamp-test facilities.
g)
Front panel switch for decimal point position.
h)
Selection of 5kHz or 2.5kHz carrier frequency.
i)
Large, bright, 4½ digit display.
j)
Shielded connectors for improved EMC.
1.2
IMPORTANT SAFETY TEST INFORMATION.
READ AND UNDERSTAND THIS MANUAL BEFORE USING THE INSTRUMENT
ELECTRICAL SAFETY CHECKS
This instrument was checked for electrical safety, using a portable appliance test instrument,
prior to despatch.
If the user wishes to carry out his own tests, the following points must be followed:
(1) This Safety Class 1 apparatus has a low (<3A) fuse rating and a low current rated
power connection cable.
(2)
It is recommended that when carrying out an earth bond test
(BS EN 61010-1
Section 6.5.1.2), the test current of 25A should not be applied for more than six
seconds.
(3)
In general it is not recommended that high voltage (e.g. 1.5kV) insulation tests are
carried out (BS EN 61010-1, Section 6). This could cause damage to suppressor
components.
3
1.2
Certificate of EMC Conformity
DECLARATION OF CONFORMITY
RDP ELECTRONICS LTD.
Grove Street Heath Town
Wolverhampton West Midlands
WV10 0PY
United Kingdom
We declare that the product described in this technical manual is manufactured
by RDP Electronics Limited and performs in conformity to the following:
The Electromagnetic Compatibility Directive 2014/30/EU
The Low Voltage Safety Directive 2014/35/EU
RoHS 2 Directive 2011/65/EU
R D Garbett
Director
RDP Electronics Limited
4
2.
2.1
INSTALLATION INSTRUCTIONS
EMC Requirements
For full EMC compliance, only shielded multi-core cables should be used for connection to
this instrument; the cable shield to be terminated by means of a short "pig-tail" and
connected to the connector cover.
The metal case should be earthed. This would usually be achieved via the green/yellow
core of the supply cable.
NOTES
1
Cable shields to be earthed at only one end - the instrument end.
2
When the instrument is a small part of a large electrical installation, ensure the
cables to and from the instrument are segregated from electrically noisy cables.
3
Ensure cables to and from the instrument are routed away from any obviously
powerful sources of electrical noise, e.g. electric motors, relays, solenoids.
4
ESD precautions should be used when working on the instrument circuit board
with the lid removed. The user should ensure he is "earthed" by use of an
earthed wrist strap or at least touching earth before touching any component
including wires, terminals or switches.
5
The body of the transducer should be earthed. If the transducer fixing
attachments to not provide a good earth, then an earth strap should be used.
Refer to Section 8 where electrical interference may be a problem.
2.2
Power Connections
Refer to section 5.2. The ac supply is connected via a 2 metre, 3-core cable (supplied) as
follows:LIVE (120/240v)
NEUTRAL
EARTH/GROUND
-
BROWN
BLUE
GREEN and YELLOW
Where a unit has an internal supply fuse, the value will be indicated in the specification. If
no fuse is specified, then an external one should be fitted, of the anti-surge type, with a
value commensurate with the VA rating of the unit as indicated in the external label.
Units should always be grounded via the supply for reasons of safety and electrical noise.
The green and yellow wire is normally internally connected to the instrument common or
0V line and hence to the transducer cable shield.
Refer also to the section on internal controls for details of supply voltage selection, and to
the Application Note on electrical interference.
5
2.3
Input and Output Signal Connections
Refer also to Fig. 3 and Rear Panel Printing.
Transducer analogue output and relay output connections are made via shielded
connectors at the rear of the instrument as shown below:
Note 1
The limit relay contacts should only be used to switch:
a)
DC resistive or reverse-diode protected inductive loads;
b)
AC resistive loads.
AC coils should be operated via a slave dc relay or SCR module.
FUNCTION
Limit Relay 1
(Note 1)
PIN No.
PLUG
Viewed from rear
N.O.
Common
N.C.
Limit Relay 2
N.O.
(Note 1)
Common
N.C.
Logic Outputs Limit 2, Limit 1
Logic/Digital Common (Mod.19
units onwards)
5
4
3
2
1
9
7, 8
6
PL1
Limits Output
9-way D-type
Display Hold Input
Lamp Test Input
Analogue Output ±10V
Analogue Output common/0V
Analogue Output 0/4-20mA
No connection
Digital 0V
Excitation +
Excitation –
Signal +
Signal –
Cable shield
1
2
3
4
5
6
7
1
2
3
4
Con.
shell
6, 7
PL2
Analogue Output/
Digital Input
7-way DIN type
No connection
5
4
9
7
6
7
3
1
2
4
6
7
3
1
5
6
2
8
5
PL3
Transducer
Connections
7-way DIN type
3
2
4
1
6
2.4
Transducer Connections (LVDT & Half bridge)
TRANSDUCER INPUT CONNECTOR
Rear view
Transducer connections are made via the 7
pin DIN connector (PL3) marked
'Transducer'. The diagram shows the REAR
view of the connector.
6
7
3
1
5
2
4
Fig. 1 Connection for LVDT Transducers
PL3 PIN
Secondary Output 1 Function
Excitation Hi
1
(Signal High)
Excitation Lo
2
Signal Hi
3
SECONDARY
Signal
Lo
4
COIL
Shield
Con. shell
Secondary Output 2 Some RDP LVDTs have
(Signal Low)
a BLACK wire. This must
Shield
be insulated.
Primary Input 1
(Excitation High)
PRIMARY
COIL
Primary Input 2
(Excitation Low)
If when connected, the phase of the amplifier output is not as required (for example, an
inward moving armature causes a rising amplifier output when a falling output is required)
then reversing the signal high and signal low wires will correct this.
Fig. 2 Connections for Differential Inductance (Half Bridge) Transducers
Excitation High
Function
Excitation Hi
PL3 PIN
1
Signal High
Excitation Lo
2
Signal Hi
3
Excitation Low
Shield
Con. Shell
Shield
In addition to these connections, it is necessary to add two bridge completion resistors to
compensate for the fact that the transducer is only half bridge. For RDP transducers, the
resistors should be 1k Ohms, high stability. These may be added in one of two places:a)
In the connector, between pins 1 and 4 and pins 2 and 4.
b)
Inside the instrument in locations R19 and R20 (see Fig. 3 for location), read 5.1
before commencing. See schematic below.
If when connected, the phase of the amplifier output is not as required (for example, an
inward moving armature causes a rising amplifier output when a falling output is required)
then reversing the excitation high and excitation low wires will correct this.
7
3.
FRONT PANEL CONTROLS
mm
RDP Trans duc er Indi c ator E309
ZERO GAIN
DP
L1
L2
LIMITS
All potentiometers are multi-turn, screwdriver-adjusted.
3.1
Zero Potentiometer
This provides fine adjustment of the display and analogue output zero levels. Its
range will depend on the setting of the Fine Gain control.
3.2
Gain Potentiometer
(Refer also to 4.1)
This provides a 2:1 adjustment of amplifier gain and is effective on both the display
and analogue outputs. Together with the Gain Range switch, allows full scale
setting for any input voltage in the specified range.
3.3
Decimal Point Switch (DP)
This is a screwdriver-adjusted rotary switch. In some positions two or three points
may be lit simultaneously: continue rotation (in either direction) until the required
point is lit.
3.4
Limits Switch
With this 3-way switch in the central (normal) position, the display monitors the
transducer signal. When set to the left (L1) the display indicates the level of Limit 1.
When set to the right, the display indicates the level of Limit 2.
3.5
Limit Level Potentiometers
These are used to set the limit levels while being monitored by the display as in 3.4.
The range of these controls is ±full scale (±19999 digits).
8
Analogue
Zero
Input
Limit
Outputs
Gain
REAR PANEL CONTROLS
0V/4mA
4.
Transducer
Gain
Outputs
PL1
4.1
PL2
SW1 SW2
PL3
Gain Range Switch & Selection
Refer also to 3.2 and Section 4.1.1
DIL switch SW2 is used to select the required amplifier gain range as shown in the
table below (Note: set lever DOWN for ON).
4.1.1 Gain switch lever selection table.
Typically, transducer manufacturers' data sheets or calibration certificates will give a
figure allowing the full-scale output to be calculated. Possible formats for this are as
follows, the examples assume a transducer range of ±50mm.
Sensitivity format
mV/V/mm
e.g. 46mV/V/mm
Explanation
To convert to F.S. output
Millivolts of output, per volt Sensitivity x 5 x range in mm
of excitation, per mm of
e.g. 0.046 x 5 x 50 = 11.5V
travel
V/V at full-scale,
Volt of output, per volt of
Sensitivity x 1
e.g. 2.3 V//V
excitation, at full-scale
e.g. 2.3 x 5 = 11.5V
mV/mm at a specified Millivolts of output, per mm (Sensitivity / specified
excitation voltage.
of travel, given a specified excitation voltage) x 0.5 x
E.g. 230mV/mm at 5V excitation voltage.
range in mm
exc.
e.g. (0.230/5) x 5 x 50=11.5V
The standard excitation of the E309 is 5V, as used in the calculations above.
The following table shows the band of transducer full-scale output voltages appropriate to
each of the 13 Gain Range Settings. For example, a transducer with a full-scale output of
11.5V would be correctly set as gain range 2, if the display was to show ±50.00mm (as in the
example above).
9
Gain Range
1
2
3
4
5
6
7
8
9
10
11
12
13
Lever(s) ON
1
1+3
1+4
1+5
2
2+3
2+4
2+5
None
3
4
5
4+5
Equivalent Input Signal Range
V rms approx.
10 to 20
10 to 20
10 to 20
13 to 20
6.5 to 13
3 to 6.5
1.5 to 3
0.8 to 1.5
0.4 to 0.8
0.2 to 0.4
0.1 to 0.2
0.05 to 0.1
0.03 to 0.05
Maximum Display
Settable
2000 to 4000
4000 to 8000
8000 to 16000
19999
“
“
“
“
“
“
“
“
“
Note for Gain Ranges 1 - 4:
The max input signal level should not exceed 20v rms otherwise non-linearity could occur.
Ranges 1 - 3 allow lower full scale display values to be used with relatively high input
signals. For example, if a F.S. value of 3000 is required for an input signal of 10v:
(a)
Multiply the required F.S. value by
20v/10v
e.g. 3000 X 2 = 6000
(b)
Choose a gain range which includes this display value, i.e. range 2 (4000 to 8000).
Notes for Gain Ranges 5 - 13:
For lower input signal levels to give less than the full 19999 display, calculate the required
gain range as for example:
To display a full scale input signal of 1.2v rms as 2500:
19999/2500 = 8
Equivalent input for full scale is 1.2 x 8 = 9.6v, therefore use gain range 5 (6.5 to 13v).
4.2
Zero Input Switch
Lever 6 on the 6-lever ZERO switch, when set to ON (down), applies zero signal to
the amplifier input (irrespective of transducer connection) to allow true amplifier
zero display/output to be set via the ZERO control. This facilitates determining
transducer centre-stroke position etc. without disconnection/linking.
4.3
Zero Suppression Switch (Coarse Zero)
Levers 1 to 5 of the 6-lever ZERO switch are used to zero the display/output when
the range of the zero potentiometer is insufficient. The table below shows the
amount and direction of display shift when different levers are switched ON. Note:
the amount of shift will vary with the setting of the Gain potentiometer:
Lever(s) ON
1
1+3
1+4
1+5
2
2+3
2+4
2+5
Display Shift (approximate) and Direction
2500 – 5000
5000 – 10000
Positive
10000 – 20000
20000
2500 – 5000
5000 – 10000
Negative
10000 – 20000
20000
10
4.4
Output Gain Potentiometer
This allows a small range of adjustment of the analogue output voltage (or current)
with respect to the full-scale display reading. The normal setting is for ±10v (or
20mA) to correspond to ±19999 display.
4.5
Output 0mA/4mA Potentiometer
This allows a small range of adjustment of the analogue output current for 0-20 or
4-20mA systems. It is normally set so that zero display corresponds to an output
current of 4mA.
4.6
Display Hold (Connector PL2)
Linking Pin 1 to Pin 7 (COM 0v) via a switch or relay holds the display value.
Alternatively, a logic signal may be used; high to run and low to hold.
Timing: Normally the display is updated at a rate of 2½ times/second, or every
400mS. When a HOLD is applied, the A-D converter will continue its full cycle
before holding the display.
The display will remain held as long as HOLD is low, but a high pulse of >300nS
will initiate a new measurement cycle. If another pulse occurs before the cycle is
complete it is ignored.
4.7
Display Test (Connector PL2)
Connecting Pin 2 to Pin 7 (COM 0v) via a switch or relay produces a 18888 display.
Alternatively, a logic signal may be applied; high for normal operation, low to test.
11
12
R20
Bridge Completion
Resistors
R19
SP1
ABCD
SP6
ABC
F1
Link A-B
For 2.5kHz
SP13 B
A
Supply
Fuse
Note: SP1 and SP6 are linked
on the underside of the PCB
E
N
L
Supply
Voltage
Frequency
Capacitor
C33
ABC
SP2
SP4
ABC
ABC
SP5 ABC
SP3
Limit 1
Mode
Limit 2
Mode
Fig. 3 Internal control locations
5.
INTERNAL CONTROLS
Refer to Figure 3 for locations.
5.1
Essential precautions prior to opening unit.
These controls are accessible, after FIRST DISCONNECTING THE SUPPLY, by
removing 6 screws from the rear panel and sliding the panel, together with the
circuit board, rearwards.
5.2
Supply Voltage
Solder links are used to select the voltage as shown below:
If you change the supply
Link
Supply
voltage setting, ensure that
SP1
SP6
the appropriate label is fitted
240 (normal)
A–B
B–C
to the outside of the unit to
120
B–C
A – B and C – D
avoid future confusion.
5.3
Limits Mode
(Refer also to Figure 4)
Solder links are used to select the mode or polarity of each limit, i.e. “high” limit or “low”
limit. Units are normally supplied so that:
(a)
the relay of Limit 1 is normally energised until the transducer signal becomes more
positive than the set point value, i.e. it operates in a fail-safe high limit mode.
(b)
the relay of Limit 2 is normally energised until the transducer signal becomes more
negative than the set point value, i.e. it operates in a fail-safe low limit mode.
Fig. 4 Limits graphic with normal mode-link setting
3a)
High or low fail safe operation.
3b)
Limits 1 and 2 levels reversed for
fail-safe band-pass operation.
Input
Input
Limit 2 relay energised
Limit 2 relay energised
Signal
Signal
(LED 2 on, logic Low)
(LED 2 on, logic Low)
Signal
Signal
Limit 2
Limit 1
Both relays energised
Setting
Setting
Both relays off (LEDs off,
(LEDs on, logic Low for
logic Low for L1, High for L2
L2, High for L1
Limit 1
Limit 2
Setting
Limit 1 relay energised
(LED 1 on, logic High)
Time
13
Setting
Limit 1 relay energised
(LED 1 on, logic High)
Time
The operating mode of each limit may be selected via the solder pads as shown below:
Limit
L1
L2
Note 1
Note 2
Note 3:
Logic
Outputs:
5.4
Links
SP2 + SP4
SP3 + SP5
Fail-Safe High
B – C (normal)
B–C
Fail-Safe Low
A–B
A – B (normal)
Two links must be changed per limit each time, e.g. to change L1 mode,
change both SP2 and SP4.
In all modes, when a relay is energised, the corresponding LED is lit.
The arrangement of the “normal” links allows use of a fail-safe pass-band
between the two limit settings.
The limits logic outputs are low (0) when the signal is more positive than the
limit value and high (1) when the signal is more negative than the limit value.
The logic is not affected by the reversing links SP2 - SP5 which operate only
on the relays and LEDs.
Frequency
On units up to Mod 20E the excitation frequency can be changed from 5kHz to
2.5kHz by fitting solder link SP13. From Mod 21 onwards the facility is not
available.
Excitation frequencies off 1 to 10 kHz are possible if stated when ordering.
14
6.
SETTING-UP PROCEDURE
6.1
Factory-Calibrated Systems
When a transducer/monitor system has been calibrated at RDP, no setting-up is
required. Connect the transducer to the rear-panel socket, switch on power and the
display indicates the transducer output directly in engineering units. In case of
problems:
(a)
Check transducer wires are not broken.
(b)
Check correct rear panel switch levers are set to ON.
6.2
Bipolar calibration (e.g. ±5.000mm display)
6.2.1 Connect the transducer, analogue output (if required) and relay output (if required)
as detailed in Section 2. Set all rear panel switch levers to OFF (up).
6.2.2 Refer to Sections 4.1 and 4.1.1 to determine which GAIN levers to set to ON.
6.2.3 Set ZERO Input lever to ON (to zero the amplifier input signal) and adjust FINE
ZERO for zero display.
6.2.4 Set ZERO Input to OFF and adjust the transducer (armature) for zero display. This
determines the transducer centre-stroke position.
6.2.5 Move the armature to the positive full-scale position and adjust FINE GAIN for the
correct display. (Note: the secondary or primary wires may be reversed to reverse
the output polarity.)
6.2.6 Re-check the zero position then move the armature to the negative full-scale
position. Check the display is correct.
The analogue output rear panel controls may be set simultaneously with steps 4
and 5.
6.3
Unipolar calibration (e.g. 0 to 10.000mm display)
Proceed as for half-stroke operation through steps 6.2.1 to 6.2.4 to determine the
transducer centre-stroke position and then:
6.3.1 Move the armature to the position where zero display/output is required and use the
gain controls to display the distance moved, e.g. if a final display of 0 to 80.00mm is
required, move the armature inwards by 40mm and set the gain controls for a
display of -40.00.
6.3.2 Refer to section 4.3 and use the Coarse Zero Switch and Fine Zero to set this
display to zero, e.g. for -40.00 use lever 1 and Fine Zero.
6.3.3 Move the armature to the full scale position and check the display is correct, e.g.
move to the +40mm position and check for 80.00 display.
Re-trim Fine Gain and Zero if necessary for consistent results.
If, for any reason, the coarse gain is changed, the whole procedure will need to be
restarted.
6.4
High Temperature LIN Transducers
Proceed as in section 6.2 but, in section 6.2.3, instead of setting the zero input
switch ON, remove the armature completely from the transducer and then set the
display to zero.
Similarly, in section 6.2.4, instead of setting the switch to OFF, replace the
armature and adjust it for zero display.
15
7.
SPECIFICATION
7.1
Display
Display size
Range
Polarity Indicator
Overrange
Decimal Points
Hold and Lamp Test
Sample Rate
7.2
Power Supply
Voltage
Power
Fuse
7.3
General
Operating Temperature
Storage
Weight
7.4
Case
Material
Bezel Size
Depth
Panel cut-out
7.5
Amplifier
Input Range
Input Resistance
Linearity
Zero Stability
11mm (0.43in) 7-segmen high brightness red LED
±19999
"-" sign displayed
Flashing display
4 positions via selector switch
Via rear terminal connections to common or TTL level
signals
400mS
240V ac standard or 120V ac selected via solder links
+10/-20%. 50/60Hz
10VA typical
250mA/S 20mm
0°C to 55°C
-40°C to 85°C
1.3kg/2.9lb
Black anodised aluminum
144 x 72mm overall
190mm (behind bezel, excluding connectors)
139 x 67mm
50mV to 20V via potentiometer and Gain Range switch
100k
±0.1% F.S. typical
0.003% FS/°C typical (display):
0.01% (analogue output)
Gain Stability
0.003% FS/°C typical (display):
0.01% (analogue output) Optimum at ± full scale
Bandwidth
300Hz (flat)
Noise p-p
5mV/10µA typical
CMRR
120dB typical
Output Voltage
±10V at 5mA
Output Current
0 or 4-20mA into 0 to 500 ohms. This is an active output
that should not be connected to any external power
supply as this will damage unit.
Protection
Short-circuit proof
Note: Outputs normally factory-set so that ±19999 display corresponds to ±10V and 0 to
+19999 display to 4-20mA
7.6
Excitation
Voltage
5V rms., 100mA max. Short-circuit proof.
Frequency
5kHz, ±5%:
1kHz-10kHz is possible if stated when ordering
7.7
Controls
Coarse Zero Adjustment
±FS via 5-lever switch
Range
16
Fine Zero Adjustment Range
Analogue Output
7.8
Limits
Set point range
Display
Indication
Mode
Relays
Operating time
Mechanical life
Accuracy
Hysteresis
Logic Outputs
7.9
Connectors
Transducer/Analogue Output
Limits Output
±2000 to ±5000 digits according to Fine Gain setting
Zero potentiometer range 0 to 10mA (for zero display).
Gain potentiometer allows setting 10V output for displays
between 2400 and 19999
(Refer also to Application Note, Section 8)
±19999 via 20-turn potentiometer
3-way switch for Limit 1/Normal/Limit 2 levels
2 LEDs on when relays on
Positive or negative going operation selected via solder
links
2 changeover contact types. 0.3A at 120V ac/1A at 24V
dc.
5mS
>12 x 106 operations
±0.1% of full scale typical
±0.05% of full scale typical
TTL Source 2mA, sink 10mA
7-pin DIN shielded. Case grounded by socket
9-pin DIN type. Case grounded by rear panel. For max.
V and I, see 7.8
17
8
APPLICATION NOTES
8.1
Electrical Interference Problems
When an E308 Transducer Indicator is used in an industrial application, some of
the following points may be helpful to System Engineers to design a trouble-free
installation.
8.11
In general the operation of electronic instruments and transducers can be affected
by electrical interference.
8.12
This interference can be generated by the switching of large or reactive loads on
the supply, causing the production of large voltage spikes and/or variation in the ac
mains supply.
Higher frequency interference (radio frequency) is often generated by a large
voltage (e.g. back e.m.f. from a coil) being switched by a contact. Generally a
contact seen to arc whilst switching is producing RF interference.
8.13
The interference "signals" can enter a transducer measuring system in the following
ways:
a)
b)
c)
Direct pick-up by wiring to the instrument. The wiring can be a connection to the
transducer supply input or control (e.g. trip relay).
Direct pick-up into the instrument.
Along the mains supply lines.
8.14
There are two methods of countering these problems:
a)
b)
Suppress the interference generation at source.
Prevent the interference gaining access to the instrumentation circuitry.
8.15
Suppression at source is often the best approach. AC coils can often effectively be
suppressed by means of connecting, as close to the coil terminals as possible, a
100 ohm resistor in series with 0.1μF across the coil. Proprietary transient voltage
clippers - either non-linear resistor or better semiconductor types - are very useful
for suppression, mounted across coils and contacts.
8.16
An electrically noisy mains supply can be suppressed by means of a mains filter
unit. These units in their simplest form consist of capacitors and inductors.
Mounted at the point where the mains enters the instrument, they can be most
effective. A constant voltage transformer is another effective way of cleaning up
the mains.
8.17
Extra shielding of the transducer, cabling and instrument is a simple, low cost
method of preventing particularly directed radiated RF type of interference.
Shielded cable should always be used to connect the transducer to the instrument.
Shielded cable is often beneficial for other connections as well. The shield should
only be earthed at the instrument end.
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It is not good practice to mount the instrument near to contactors, motors, switch
transformers, solenoids, etc. But where it is considered necessary to mount the
instrument near to such devices, an extra steel enclosure around the instrument
would be essential.
In extreme cases, the transducer cable should be run in a steel conduit.
8.18
Trip relays fitted inside the E308 should never be used to switch ac coils. The
recommended arrangement is to use a dc slave relay as shown below.
d.c. Supply
+ -
a.c. Input
RLS/1
Suppression
Diode
Transient
Clipper
Solenoid
RLS Slave
Relay
Wherever possible, TTL limit outputs should be used to:
a)
b)
c)
reduce noise problems,
increase response speed,
increase life especially in repetitive applications where relay contact life may be
significant.
8.2
Bench/portable instrument
The bench instrument (BI) version of the E309 instrument is a standard E309 mounted in
an additional case incorporating the following features:
(a)
extra physical protection
(b)
carrying handle
(c)
front panel dial-type ZERO control.
The standard E309 Technical Manual is applicable except that the overall dimensions of
the BI case are:
Height 94mm
Width 216mm
Depth 235mm
and the weight is 2.1kg (4.6lb).
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9
WARRANTY AND SERVICE
WARRANTY.
R.D.P. Electronics products are warranted against defects in materials or workmanship.
This warranty applies for one year from the date of delivery. We will repair or replace
products that prove to be defective during the warranty period provided they are returned
to R.D.P. Electronics.
This warranty is in lieu of all other warranties, expressed or implied, including the implied
warranty of fitness for a particular purpose to the original purchaser or to any other
person. R.D.P. Electronics shall not be liable for consequential damages of any kind.
If the instrument is to be returned to R.D.P. Electronics for repair under warranty, it is
essential that the type and serial number be quoted, together with full details of any fault.
SERVICE.
We maintain comprehensive after-sales facilities and the instrument can, if necessary be
returned to our factory for servicing.
Equipment returned to us for servicing, other than under warranty, must be accompanied
by an official order as all repairs and investigations are subject to at least the minimum
charge prevailing at the date of return.
The type and serial number of the instrument should always be quoted, together with full
details of any fault and services required.
IMPORTANT NOTES.
1.
No service work should be undertaken by the customer while the unit is under
warranty except with the authorisation of RDP Electronics.
2.
If the instrument is to be returned to R.D.P. Electronics for repair, (including repair
under warranty) it is essential that it is suitably packed and that carriage is insured
and prepaid. R.D.P. Electronics can accept no liability whatsoever for damage
sustained during transit.
3.
It is regretted that the above warranty only covers repairs carried out at our factory.
Should the instrument have been incorporated into other equipment that requires
our engineers to perform the repair on site, a charge will be made for the engineer's
time to and from the site, plus any expenses incurred.
The aforementioned provisions do not extend the original warranty period of any product
that has been either repaired or replaced by R.D.P. Electronics.
THIS WARRANTY MAY BE NULL AND VOID SHOULD
THE CUSTOMER FAIL TO MEET OUR TERMS OF PAYMENT.
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