Grundfos DDA 7.5-16 User Manual

English (GB)
43
* Depending on setting
8.1.2 General faults
Pressure sensor
(Warning)
• Broken "FlowControl" cable (see
fig. 11)
• Sensor defect
• Pressure sensor not correctly
calibrated.
• Check plug connection.
• Change sensor if necessary.
• Calibrate pressure sensor correctly (see
section 6.8.2 Calibration of pressure
sensor).
Motor blocked
(Alarm)
• Backpressure greater than
nominal pressure
• Damage to gears
• Reduce backpressure.
• Arrange for repair of gears, if necessary.
Bus error
(Alarm)
• Fieldbus communication error • Check cables for correct specification and
damage; replace if necessary.
• Check cable routing and shielding; correct
if necessary.
E-Box
(Alarm)
• E-Box connection error
• Faulty E-Box
• Check plug connection.
• Replace E-Box if necessary.
Cable break
(Alarm)
• Defect in analog cable 4-20 mA
(input current < 2 mA)
• Check cable/plug connections and
replace, if necessary.
• Check signal transmitter.
Service now
(Warning)
• Time interval for service expired • Perform service (see section 7.4 Perform
service).
Display in the
"Alarm" menu
Possible cause Possible remedy
Fault Possible cause Possible remedy
Dosing flow too high
Inlet pressure greater than
backpressure
Install additional spring-loaded valve (approx.
3 bar) on the discharge side.
Increase pressure differential.
Incorrect calibration
Calibrate the pump (see section 5.3 Calibrating
the pump).
No dosing flow or
dosing flow too low
Air in dosing head Deaerate the pump.
Faulty diaphragm
Change the diaphragm (see section 7.4 Perform
service).
Leakage/fracture in lines Check and repair lines.
Valves leaking or blocked Check and clean valves.
Valves installed incorrectly
Check that the arrow on the valve housing is
pointing in the direction of flow. Check whether all
O-rings are installed correctly.
Blocked suction line Clean suction line/install filter.
Suction lift too high
Reduce suction lift.
Install priming aid.
Enable "SlowMode" (see section 6.6 SlowMode).
Viscosity too high
Enable "SlowMode" (see section 6.6 SlowMode).
Use hose with larger diameter.
Install spring-loaded valve on the discharge side.
Faulty calibration
Calibrate the pump (see section 5.3 Calibrating
the pump).
Deaeration valve open Close the deaeration valve.

Grundfos DDA 7.5-16 Specifications

General

Max Flow Rate	7.5 l/h
Max Pressure	16 bar
Protection Class	IP65
Operating Temperature	0°C to +45°C
Analogue Control	4-20 mA
Pulse Control	Yes
Level Control	Yes
Power Supply	100-240 V, 50/60 Hz
Material	Stainless Steel