sauermann ECM 88 ECM-Electric Contact Pressure Controllers User Guide
- June 6, 2024
- sauermann
Table of Contents
sauermann ECM 88 ECM-Electric Contact Pressure Controllers
The ECM electric contact pressure controllers are the result of a long
experience in the research and manufacture of measuring and control
instruments.
They are designed to combine the inherent reliability and accuracy of the
liquid column manometer with electronic switching.
The Sauermann ECM electric contact pressure controllers excel where it is
necessary to monitor small variations in low pressures of air or gas.
Operation
The ECM can be fitted to a vertical or inclined manometer. The photoelectric
sensor is connected to a PCB by an optical fiber.
When energized the PCB generates an infrared ray that travels along with the
optic fiber and through the manometer’s liquid column.
The PCB senses when the liquid column breaks the infrared ray and operates the
switch either making or breaking the contact depending on how it is set.
The ECM can operate on rising or falling pressure by changing the position of
the “inverter switch” on the PCB.
Diagrams 1 and 2 show the operation principle. The switch operates when the
pressure rises and the manometer liquid breaks the infra-red ray at 100 mm H2O
also lighting the LED.
When the inverter microswitch is operated (diagram 2) the switch operates when
the pressure falls and the infra-red ray is re-established at 100 mm H2O.
The changeover relay enables the power to be switched on or off with a delay
of up to 45 seconds. Multiple units can be fitted to one manometer column to
perform different functions.
- Manometer to zero
- Powered PCB
- Inverter” micro-switch
- Established infra-red ray
- LED – off
- Broken “relay contact”
- Manometer pressurized
- Infra-red ray cut off
- LED – on
- Made “relay contacts”
Checking operation
- The sensitivity of the photoelectric cursor is adjusted in the factory but we recommend that you check the operation (as described in section 5) and adjust this setting, if necessary before you install the instrument.
- The instrument must be securely fixed to a wall or rigid bracket, independent of pipework or vibration.
- The instrument should be protected from adverse environments and heat sources.
- It is important to use the correct density manometer liquid AWS 10 or VOLT 1S depending on the model (consult us).
Manometric liquid
After fixing and leveling the ECM controller, unscrew the right-hand
connection (viewed from the front) and slowly pour the manometer fluid, using
the spout on the bottle, up to the zero point on the scale.
Replace the connection. If necessary make fine adjustments to the zero point
by moving the graduated scale. Connect the manometer to the pressure or vacuum
source with clear tubing.
-
For a positive pressure (+), connect the tube to the left-hand connection of a vertical manometer, and to the right-hand connection of an inclined
manometer. Make the opposite connections for vacuum. -
For differential pressure measurement: connect the higher pressure (before the filter) to the manometer (+) connection and the lower pressure to the manometer (-) connection (after the filter).
Connection
Detection sensitivity setting
The detection sensitivity of the photoelectric cursor is adjusted in the factory. After filling the manometer, with the correct density manometer liquid, it is recommended that you check this setting before putting the unit into service.
PROCEDURE:
Apply the voltage to the electronic card, but do not connect the relay. Turn
the temporizing potentiometer to zero (fully anti-clockwise) and put the
function inverter switch to the “normal” position (Figure 1 shows the switch
in the “inverted” position).
The unit can then be operated by tilting the unit to the right, causing the
manometer liquid to pass the cursor.
When the voltage is applied, various things can happen:
-
Switching is OK, the sensitivity setting (adjusted in the factory) is in the center of it’s range (10 to 12 rotations). The unit is ready to put into service.
-
The red LED is “on”, the relay energized and there is no change when the manometer liquid passes the cursor. If the red LED switches “off” and the relay de-energizes when the inverter switch position is changed, this means that the cell is too powerful.
Turn the setting potentiometer anti-clockwise, until the red LED is switched off and then turn a further 5 rotations.
Displace the manometer liquid past the cursor and ensure that there is a sure and repeated switching action. -
The red LED is “off”, the relay is de-energized, there is no action when the manometer liquid passes the cursor.
When the inverter switch is operated the LED switches “on” and the relay energizes, but there is no change when the manometer liquid passes the cursor. This means that the cell is not powerful enough.
Make sure the liquid is past the cursor and then turn the potentiometer clockwise until the LED and relay switch, then turn a further 5 rotations.
Displace the manometer liquid past the cursor and ensure that there is a sure and repeated switching action. -
When the voltage is applied the red LED and relay flicker with no liquid covering the cursor. This means that the sensitivity is set too high, turn the potentiometer anti-clockwise approximately 4 or 5 rotations.
Displace the manometer liquid past the cursor and ensure that there is a sure and repeated switching action.
Before carrying out the setting procedures above:
- Make sure the manometer is filled with liquid, up to its zero point.
- The temporizing potentiometer is set to zero (fully anti-clockwise).
- Function inverter switch in a logical position.
- The electronic card is powered and the relay is disconnected.
Options
To avoid the manometer liquid being blown out, in the case of
overpressurization, the instrument can be fitted with safety valve connections
type 509 (consult us).
Services
The ECM does not need any regular service. We simply recommend that the
manometer liquid is changed every year, to ensure that the photoelectric cell
works properly.