KSB Ama-Drainer 4 Series, Installation & Operating Manual

Page: 22 / 60

5 Installation at Site
22 of 60
Ama-Drainer 4../5..
5.5.2 Setting the overload protection device
1. Protect the pump set against overloading by a thermal time-lag overload
protection device in accordance with IEC 60947 and local regulations.
2. Set the overload protection device to the rated current specified on the name
plate. ( ð Section 4.3, Page 15)
5.5.3 Connecting the level control equipment
CAUTION
Fluid level below the specified minimum
Damage to the pump set by cavitation!
▷ Never allow the fluid level to drop below the specified minimum.
NOTE
The pump set is switched ON/OFF with the float switch at an UPWARD/
DOWNWARD slant of approximately 40° of the float housing (clearly audible
switching noise in the float housing).
Automatic operation of the pump set in a tank requires the use of level control
equipment.
Observe the minimum fluid level. (
ð
Section 6.2.3.2, Page 28)
The SE and SD variants are equipped with a float switch. Set the switching level on
site.
Conditions to be met when setting the switching levels
▪ Observe the minimum fluid level. ( ð Section 6.2.3.2, Page 28)
▪ The pump set stops before the water level falls to the level of the pump foot's
suction openings.
▪ The pump set starts up before the water level reaches the upper edge of the
tank.
▪ The float switch must neither come to rest at the bottom nor hit against
anything at the top.
▪ The switching difference equals 40 cm as a minimum.
When installing two pump sets and one control unit for dual-pump stations, arrange
the two float switches in a cascade. This configuration permits three switching
functions:
▪
Alternating start-up of the two pump sets for each switching cycle.
▪ Additional start-up of the stand-by pump at peak load.
▪ Start-up of the stand-by pump should the duty pump fail.
Setting the switching levels
1. Choose an appropriate height for attaching the float switch cable.
2. Attach the float switch cable to the discharge line, the lifting lug at the handle
4)
or to another suitable point.
4) On variant R the lifting lug at the handle cannot be used as an attachment point.