98
Examples:
Booster unit
Problem: no stop of the HYDROVAR
Parts to check
measure
•
existing demand
•
non return valve is not closed
•
pre charge pressure in the pressure tank
•
incorrect setting
of WINDOW and
RAMPHYSTERESIS
•
shut down ramp too slow
•
suction line too long
•
check pipes and valves
•
change non return valve
•
adjust according the diagram
•
set WINDOW [0310] (ca.10%) and
HYSTERESIS [0315] (80-50%)
•
set RAMP 2 [0220] to 4...13 sec.
•
the MINIMUM FREQUENCY [0250] should be
activated for pressure increase at 0 demand
Control on constant flow
Problem: control fluctuations
Parts to check
measure
control characteristics are set too low
enlarge
r
WINDOW [0310] and set
HYSTERESIS [0315] to 99% to control with
RAMP 3 and 4
Circulating pump
Problem: oscillation of the motor speed
Parts to check
measure
control settings too fast
•
increase RAMP 3 [0225] and 4 [0230]:
100...200sec
•
WINDOW [0310] (ca.20%) and
HYSTERESIS [0315] (ca.99%)
Problem: ACTUAL VALUE can't be hold
Parts to check
measure
HYSTERESIS is set too big
HYSTERESIS [0315]: 90-99%
General
Problem: pressure fluctuations, analogue signal not constant
Solution:
•
check cables and connection of the screen
•
check earth connection of the transmitter cable
•
use screened cables
