PM856K01 AC 800M PM856 3BSE018128R1 ABB CPU controller

Product Details

Product Description

Product Description
PM856K01 AC 800M PM856 3BSE018128R1 ABB CPU controller
PM856K01 AC 800M PM856 3BSE018128R1 ABB CPU controller
Our Email: 2235954483@qq.com
contact number:13313705507
contacts：HE
Fault a: the fault, without negligible impedance, between the two polarities
sets up a short-circuit current to which both polarities contribute to the full
voltage, according to which the breaking capacity of the breaker must be
selected.
• Fault b: the fault between the polarity and earth has no consequences from
the point of view of the function of the installation.
• Fault c: again, this fault between the polarity and earth has no consequences
from the point of view of the function of the installation.
In insulated networks it is necessary to install a device capable of signalling the
presence of the first earth fault in order to eliminate it. In the worst conditions,
when a second earth fault is verified, the breaker may have to interrupt the
short-circuit current with the full voltage applied to a single polarity and therefore
with a breaking capacity which may not be sufficient.
In networks with both polarities insulated from earth it is appropriate to divide
the number of poles of the breaker necessary for interruption on each polarity
• Fault a: the fault between the two polarities sets up a short-circuit current to
which both polarities contribute to the full voltage U, according to which the
breaking capacity of the breaker is selected.
• Fault b: the fault on the polarity not connected to earth sets up a current
which involves the over-current protection according to the resistance of the
ground.
• Fault c: the fault between the polarity connected to earth and earth has no
consequences from the point of view of the function of the installation.
In a network with one polarity connected to earth, all the poles of the breaker
necessary for protection must be connected in series on the non-earthed
polarity. If isolation is required, it is necessary to provide another breaker pole
on the earthed polarity