Tescom ER1200 Series, ER1200-1-1, ER1200-1, ER1200-2, ER1200-2-1 Operation & Service Manual

Form # 1925 Rev. 4/06 TESCOM

TABLE OF CONTENTS

Page

GENERAL OPERATION

ER1200 Versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Internal Feedback Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

External Feedback Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

ELECTRICAL INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

ER1200 CONFIGURATION

Configure Setpoint Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Configure Analog Output Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Configure Feedback Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TUNING THE ER1200

Deadband . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Zero & Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Gain & Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

TROUBLE SHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

ER1200

Operations &

Service Manual

Form # 1925 Rev. 4/06 TESCOM

1

GENERAL OPERATION

INTRODUCTION

The ER1200 is a closed loop pressure control system capable of operating in two different modes.
In the “Internal Feedback” mode, the control is based on the internal pressure sensor, which has a
range of 0 - 100 PSIG. In “External Feedback” mode, the PID algorithm is based on an external,
customer provided transducer. The ER1200 requires both a setpoint, which is the desired output
pressure, and a feedback, the actual output pressure.

INTERNAL FEEDBACK MODE

In internal mode, the ER1200 compares the
feedback signal from the internal pressure
sensor to the setpoint input. Inside the unit,
there are two solenoid valves that control the
output pressure. If the feedback signal is
below setpoint, the ER1200 opens its inlet
valve and increases output pressure. If the
feedback is above setpoint, the ER1200
opens its exhaust valve to decrease the
output pressure. Every 25 milliseconds, the
feedback is compared to the setpoint and a
correction is made to make the output
pressure equal to the desired.

Inlet pressure:

Typical – 110 PSIG
Maximum – 120 PSIG
Minimum – 10 PSIG above required controlled
output pressure

ER1200 VERSIONS

This manual is a comprehensive documentation of specifications and operations of all versions of
the ER1200 Series regulator. The following table summarizes the differences in features for
different ER1200 versions. Use this table to check the version number of your ER1200. The
versions without an internal sensor do not have an “internal feedback” mode option.

PART NUMBER INTERNAL SENSOR 18" CABLE AND WATER TIGHT CONNECTOR

(0-100 PSIG) STRAIN RELIEF AND 2' MATING CABLE

ER1200-1 Yes Yes No

ER1200-2 Yes No Yes

ER1200-1-1 No Yes No

ER1200-2-1 No No Yes

Figure 1

Form # 1925 Rev. 4/06 TESCOM

GENERAL OPERATION Continued

2

EXTERNAL FEEDBACK MODE

In External Feedback mode, the ER1200 can
be used to control flow, position, temperature,
or any other variable that can be affected by a
change in pressure. For the purpose of this
operation manual, we will discuss the control
of pressure. In this mode, the ER1200
compares an external feedback signal from a
customer supplied transducer to the setpoint.
Typically, this mode is used when the ER1200
is combined with either a pressure reducing or
back pressure regulator (shown with a ratio
actuated, pressure reducing regulator, Figure 2).
If the feedback signal is below setpoint, the
ER1200 opens its inlet valve and increases
output pressure. This increases pressure on
the dome of the regulator, opening the main
valve and increasing downstream pressure. If
the feedback is above setpoint, the ER1200
opens its exhaust valve, which decreases
dome pressure, allowing the regulator to
decrease output pressure.

Pressure Connections:

ER1200 inlet pressure is the same as in
internal mode. Refer to regulator installation
and operation instructions and the product
label for maximum inlet pressure information.

Figure 2

SPECIFICATIONS

Enclosure

NEMA 4 housing

Mounting

2 10-32 UNF mounting holes

Power Requirement

24 Volts DC +/- 2 volts
150 milliAmp typical current draw

Input Signals

All signals are field configurable using
onboard jumpers:
Setpoint: 4-20 mAmp, 1-5 VDC or

0-10 VDC

Feedback: Internal (0-100 PSIG) or

external
External
Feedback: 4-20 mAmp, 1-5 VDC or

0-10 VDC

Inlet Pressure

Maximum: 120 PSIG
Typical: 110 PSIG
Minimum: 10 PSIG above desired

output pressure

Media

Clean, dry, inert gas

Environment

Temperature: -10°F to +150°F

Flow Stream Materials

300 Series SST, Buna-N, 6000 Series
Aluminum, Brass, Nickel, Silicon, Gold,
Glass, RTV

Performance

Total Accuracy: +/- 0.25%
Linearity: +/- 0.1%
Repeatability: +/- 0.12%
Flow Capacity: Cv= 0.03

3

Form # 1925 Rev. 4/06 TESCOM

1 White + Setpoint

2 Brown - Setpoint

3 Green + Feedback

4 Yellow + Analog Output

5 Black Power Ground

6 Red + TTL Output

7 Orange + 24 VDC Power

8 Violet* Secondary Ground

Wire Number Wire Color Function

ELECTRICAL INSTALLATION

*Not available for ER1200-2 and ER1200-2-1

Form # 1925 Rev. 4/06 TESCOM

4

Current Setpoint - Active Source

Voltage Setpoint

Current Setpoint - Passive Source

ER1200 CONFIGURATION

There are two printed circuit boards inside
the ER1200. The bigger, vertical board is
the control board. All the jumpers used to
configure the ER1200 are located on this
board. The tuning and calibration pots are
also located on the control board. (See

page 6 for details on tuning the ER1200.)

The smaller, horizontal board has two pots
used to zero and span the internal sensor.
These pots are set at the factory and should
NOT be adjusted.

CAUTION: CONFIRM POWER SUPPLY
IS OFF BEFORE MOVING JUMPERS.

CONFIGURE SETPOINT SIGNAL

MODE – JP1

• Current Setpoint Mode:

Install Jumper

• Voltage Setpoint Mode:

Remove Jumper

RANGE – JP2

• 4-20 mAmp/1-5 Volts:

Install Jumper on pins 1 & 2

• 0-10 Volts:

Install Jumper on pins 2 & 3

CONFIGURE ANALOG OUTPUT SIGNAL

MODE – JP6

• Current Output Mode:

Not available

• Voltage Output Mode:

Install Jumper on pins 2 & 3

RANGE – JP7

• 1-5 Volts:

Install Jumper on pins 1 & 2

• 0-10 Volts:

Install Jumper on pins 2 & 3

CONFIGURE FEEDBACK SIGNAL

MODE – JP5

• Current Feedback Mode:

Install Jumper

• Voltage Feedback Mode:

Remove Jumper

RANGE – JP4

• 0-10 Volts:

Install Jumper on pins 1 & 2

• 4-20 mAmp/1-5 Volts:

Install Jumper on pins 2 & 3

SOURCE – JP3

• Internal Feedback Mode:

Install Jumper on pins 1 & 2

• External Feedback Mode:

Install Jumper on pins 2 & 3

5

Form # 1925 Rev. 4/06 TESCOM

Figure 3

TUNING THE ER1200

There are 5 adjustments located on the control
card. The initial factory pot settings are listed
in the following table.

CLOCKWISE

FUNCTION TURNS

Gain 11

Stability (Integral) 5

Deadband 7

Zero 18

Span 13

Note: The counter-clockwise end point from
which to start turning the pots is found by
rotating the pot counter-clockwise 25 turns.

• The easiest method for calibrating and
tuning the system is to use a volt meter to
monitor the setpoint and feedback voltages.

• Turn all the pots back to the factory settings.

• Apply a setpoint signal of at least 12.5%
(6 mAmps, 1.5 VDC if 1 - 5 VDC, or 1.25
VDC if 0 - 10 VDC).

• Rotate the Deadband pot until exhaust gas
can barely be felt escaping from the
exhaust port (see Figure 1, page 1) on the
base of the unit. Rotating the deadband pot
clockwise will decrease the deadband to the
point that the inlet and exhaust solenoid
valves will operate continuously. This will
result in a very accurate tracking response,
but obviously consumes gas. If the
deadband is increased by rotating the pot
counter-clockwise, pilot gas will be
conserved, but the system will not respond
to a change in setpoint or feedback until the
error signal is larger than the imposed
deadband voltage. This can result in drifting
of the feedback signal or no response to a
small change in setpoint signal.

• Apply a setpoint signal of about 2.5% (4.4
mAmps, 1.1 VDC if 1 - 5 VDC, or 0.25 VDC
if 0 - 10 VDC). Measure the feedback signal
and adjust the zero pot until the feedback
signal matches the setpoint signal. Rotating
the zero pot clockwise will increase the
feedback signal and a counter-clockwise
rotation will decrease the feedback signal.
Sufficient time should be given for the
system to respond between each
adjustment of the pots, especially if there is
a large control volume. Rotate the pots
slowly and observe the system reaction.

Zero Pot Rotation Effect

Figure 4: Zero Adjustment

• Apply a setpoint signal of about 95% (19.2
mAmps, 4.8 VDC if 1 - 5 VDC, or 9.5 VDC if
0 - 10 VDC). Measure the feedback signal
and adjust the span pot until the feedback
signal matches the setpoint signal. Again,
sufficient time should be given for the
system to respond between each
adjustment of the pots. Since the zero and
span adjustments interact with one another,
it is necessary to readjust the zero after
adjusting the span. Recheck the zero and
adjust it if the feedback signal does not
match the setpoint signal of 2.5%. Continue
to recheck zero and span until the feedback
signal and setpoint signal match at both the
low and high setpoint values.

6

Form # 1925 Rev. 4/06 TESCOM

Output

Signal (mA)

TUNING THE ER1200 Continued

Span Pot Rotation Effect

Figure 5: Span Adjustment

Typically, Gain and Stability adjustments are
not needed. However, the following general
guidelines can be followed to fine tune your
system:

Rotating the gain pot clockwise increases the
system gain and decreases the system
response time. Too little gain will result in slow
response and inaccurate signal tracking. Too
much gain will result in system instability, fast
vibration, or in the feedback signal
overshooting the setpoint signal when a large
step change in setpoint is initiated.

Rotating the stability pot clockwise will
decrease the reset time and quicken the
addition of gain into the system. This can
again result in setpoint overshoot. Rotating
the pot counter-clockwise will increase the
reset time and dampen the control response
to a step change in setpoint.

The stability adjustment does not interact with
any of the other adjustments, however, if the
gain or deadband pots are turned at this point,
the zero and span will need to be readjusted
per the procedure outlined above.

Reaction To Step Change In Setpoint

Figure 6: System Response

If the system is experiencing a slow oscillation,
decrease the gain by rotating the pot counter­clockwise until the oscillation stops. If the
oscillation is rapid, increase the reset action by
rotating the stability pot clockwise until the
oscillation stops. These settings will be the
maximum gain and minimum reset time that
can be used with the system as it is configured.
If the feedback signal severely overshoots the
setpoint signal when a change in setpoint is
made, turn the stability pot counter-clockwise
alternately with the gain pot (also counter­clockwise), until the overshoot is eliminated.

For very precise tuning of the control, a dual
channel storage oscilloscope is recommended
so that the user can see the effect of gain and
integral adjustment on the response of the
system. One channel of the scope is used to
monitor the setpoint voltage and the other
channel to monitor the feedback voltage. The
gain and integral adjustments have the
greatest effect on the system response to a
step change in setpoint signal. The control
can be tuned in this fashion for millisecond
response to step changes in setpoint from 0 to
100%. Remember, after adjusting the gain
pot, the control will need to have its zero and
span readjusted.

7

Form # 1925 Rev. 4/06 TESCOM

Output

Signal (mA)

Under Damped

Critically
Damped

Over Damped

Feedback Response

0

Time

TROUBLESHOOTING

ER1200 Symptom Cause Remedy

8

Form # 1925 Rev. 4/06 TESCOM

Unable to maintain outlet
pressure

Positive output pressure
with zero setpoint

Outlet pressure is equal
to inlet pressure

Outlet pressure does not
follow setpoint changes

Outlet pressure becomes
uncontrollable (unstable
or unable to establish
setpoint)

ER1200 exhaust valve
leaking

ER1200 supply pressure is
not high enough

ER1200 inlet solenoid valve
leaking

ER1200 supply pressure
exceeds the maximum

ER1200 not getting a
feedback signal

ER1200 jumpers not
configured correctly

ER1200 GAIN, INTEGRAL,
or DEADBAND are out of
adjustment

The feedback signal reacts to
a process change at a slower
bandwidth than the ER1200
(25 milliseconds)

There are leaks in the
downstream pressure line

The system design has
components that can cause a
delay in down stream
transducer response while
the up stream pressure is
allowed to build up (pressure
differential between
measurement point and
source)

Return unit to factory for
replacement of valve

Check the incoming pressure
to the ER1200 and ensure that
it is between 10 to 20 PSIG
above the maximum desired
output pressure

Return unit to factory for
replacement of valve

Lower supply pressure to less
than 115 PSIG

Check transducer wiring and
feedback jumper settings

Reconfigure jumper settings
according to page

Read TUNING THE ER1200
(page 6) in this manual and
readjust the gain and pots per
that section

Replace the transducer with
one that has a full range
response time at least as fast
as that of the ER1200

Locate and eliminate all leaks

Eliminate the flow restriction, or
slow down the ER1200
response time by restricting the
flow of supply pressure into the
ER1200

Form # 1925 Rev. 4/06 TESCOM

Tescom

Industrial Controls
Systems Group
12616 Industrial Boulevard
Elk River, Minnesota 55330-2491
Toll Free 800-447-1250
Tel [phone]
Fax [phone]
e-mail: [e-mail]
www.TESCOM.com