Underload monitor (Cos-phi monitor)
BA 9065

The underload monitor BA 9065 measures the phase shift between voltage and current. The phase angle changes with changing load. This measuring method is suitable to monitor asynchronous motors on underload and no load independent of motor size. The change of cos ϕ has to be bigger then the hysteresis of the monitor. In some cases the cos ϕ does not change much with load change on the motor.
Monitors underload and no load on squirrel cage motors e.g.
- fan monitoring (broken belt)
- filter monitoring (blocked filter)
- pump monitoring (blocked valve, dry running)

Features
. According to IEC/EN 60255-1
. Detection of underload (cos ϕ)
. Current ranges up to 10 A, for higher values a CT must be used
. Adjustable response value
. Programmable functions:
- Alarm when I = 0
- Sutomatic or manual reset
- Closed or open circuit operation
. Manual remote reset
. Adjustable operate delay
. Independent of phase sequence
. Also for 400 Hz systems
. Optionally for motors with frequency converters (10 ... 100 Hz) (see notes)
. Width 45 mm

Technical specifications
Width: 45mm
Operate delay: Yes
Enclosure design: Switch cabinet
1- / 3-phase: 3, 1
Measuring range max.: 10 A
Output contacts: 1 C/O contact, 1 NO contact
Auxiliary voltage: AC, Without
Type: BA 9065


Manufacturer: E. Dold & Söhne GmbH & Co. KG
Type: BA9065.20 3AC380-440V 0,5-10A
Art. No.: 0039727