Setting The Dosing Flow Automatically With The Vga-113-311 Dosing Regulator; Emergency Operation; Stopping The Chlorine Gas Dosing System - Grundfos Vaccuperm VGA-113 Installation And Operating Instructions Manual

7.4 Setting the dosing flow automatically with the
VGA-113-311 dosing regulator
The VGA-113-311 dosing regulator is checked and preadjusted in
the factory with the servomotor. It can be readjusted on site.
• Servomotor type Tensor Basic (4-20 mA version): adjust the end
positions and the respective mA setpoints.
• Servomotor type Nano (potentiometer version): adjust the limit
switches.
Read the enclosed supplier manual of the servomotor
used.

7.5 Emergency operation

Make sure that the limit switch stops the servomotor
before the mechanical stop at the adjusting spindle is
reached.
The servomotor torque can damage the coupling and
mechanical parts.
7.5.1 Disconnecting the servomotor for emergency operation
If the servomotor is damaged, or for maintenance tasks, the
servomotor can be disconnected from the rate valve of the dosing
regulator. The automatic dosing regulator can then be operated
manually.
1
Disconnecting the servomotor from the rate valve
1. Switch off the power supply of the servomotor.
2. Slide the coupling (1) upwards.
3. Push the retention pin (2) through the coupling, until the
coupling cannot move down any longer.
The servomotor is disconnected from the rate valve. Now the
dosing flow can be adjusted manually.
7.5.2 Reconnecting the servomotor
2
Reconnecting the servomotor to the rate valve
1. Push back the retention pin (2).
2. The coupling slides down.
3. Turn the adjusting knob (3), until the coupling snaps in.
The servomotor is connected again.
12

7.6 Stopping the chlorine gas dosing system

7.6.1 Stopping the chlorine gas dosing system in case of
emergency
1. Immediately close the chlorine container valves.
2. Let the system run until all parts are evacuated.
3. Stop the chlorine gas dosing system.
7.6.2 Stopping the chlorine gas dosing system for a short time
1. Close the rate valve at the dosing regulator using the adjusting
knob.
2. Stop the booster pump.
3. Close the motive-water valves.
4. Close the shut-off valve at the injection unit.
7.6.3 Shutting down the chlorine gas dosing system for a long
time
2
1. Close all chlorine container valves.
2. Let the system run, until the flowmeter of the dosing regulator
shows no flow.
3. Close the rate valve at the dosing regulator using the adjusting
knob.
4. Switch off the booster pump.
5. Close the motive-water valves.
6. Close the shut-off valve at the injection unit.
3
Do not stop the chlorine gas dosing system by closing the
rate valve.
The rate valve is an adjusting valve, not a shut-off valve.
WARNING
Toxic material
Death or serious personal injury
‐
If gas escapes, immediately leave the room.
‐
Put on personal protective equipment.
‐
Start countermeasures according to local safety
regulations.