12
Air Circuit Breakers
BT2 series
Test functions
Panel button
Type L25, M25, M26,
H26, P25, P26
Release
Inspeciton of T-I characteristic of the OCR and the conditions of operating mechanism
Type M25, M26, H26,
P25, P26
Non-release
Inspeciton of T-I characteristic of the OCR
• Contact wearing indication (for M25, M26, H26, P25 and P26)
The intelligent controller has the function of contact wearing
indication. Accordingly, the percentage of the equivalent to
wearing times of main contact to electrical life-span times of
the circuit breaker can be indicated by pushing the button of
"wearing indication".
• Self-diagnosis function (for M25, M26, H26, P25 and P26)
When the microprocessor of the intelligent controller breaks
down or the ambient temperature of the microprocessor rises
over 80°C±5, alarm signals can be sent out immediately.
• MCR function
When the circuit breaker is on or the controller is initially
electrified, the circuit breaker would trip instantly if short-time
short circuit fault occurred.
• Fault-memory function (for M25, M26, H26, P25 and P26)
The types and phases of fault, value of faulty current and
breaking time would be indicated on the intelligent controller if
the circuit breaker broke off as a result of faults.
• Current disequilibrium display (selective function for P25 and P26)
The intelligent controller can sent out and display, when the
three phases current disequilibrium level reached the setting
value (20%-80%).
Note: the three phases current disequilibrium=
Imax-Imin
Imax
×100%
• Harmonic analysis function (for P25 and P26)
P25 or P26 intelligent controller with harmonic analysis
function can measure fundamental current, fundamental
line voltage, fundamental phase voltage, fundamental power,
odd harmonic current ratio (HRIh) from the third to thirty-first,
harmonic voltage ratio (HRUh), total harmonic distortion of
current (THDi, thdi) and total harmonic distortion of voltage
(THDu, thdu).
• Harmonic ratio (HR)
The ratio of RMS of hth harmonic component in the periodical
alternating quantum to RMS of fundamental component (express
by percent).
• Harmonic current ratio of hth expresses HRI
h
.
HRI
h
= I
h
I
1-1
×100%
Note: I
h
-harmonic current of hth of phase A (RMS)
• Harmonic voltage ratio of hth expresses HRU
h
.
HRU
h
=
U
h
U
12-1
×100%
Note: Uh -harmonic line voltage of hth between phase A and B.
• Total harmonic distortion (THD)
• The ratio of harmonic content in the periodical
alternating quantum to RMS of fundamental component
(THD)(express by percent).
THD
i
=
I
2
h
I
1-1
×100%
THD
u
=
U
2
h
U
12-1
×100%
Note: I
h
-harmonic current of hth of phase A (RMS)
U
h
-harmonic line voltage of hth between phase A and B (RMS)
• The ratio of harmonic component in the periodical
alternating quantum to RMS of periodical alternating
quantum(thd) (express by percent).
thd
i
=
I
2
h
I
1-1
×100%
thd
u
=
U
2
h
U
12-1
×100%
Ntoe: I
h
-harmonic current of hth of phase A (RMS)
U
h
-harmonic line voltage of hth between phase A and B (RMS)
Intelligent controller
