ABB Distribution Protection Unit 1500R
1-2
Protective Functions
9/99
website:www.abb.com/papd
The 51P element can be su-
pervised (torque controlled)
by mapping the “PH3” logi-
cal input to a physical input
for external supervision or
Logical Output for internal
supervision. See the Pro-
grammable I/O” Section for
programming instructions.
There are two selectable re-
set modes available for the
51P element. The instan-
taneous mode is used to
coordinate with other instan-
taneous reset devices such
as solid state or micropro-
cessor based relays. In the
instantaneous mode the
51P will reset when the cur-
rent drops below the pickup
setting for one half cycle.
The delayed mode simu-
lates the action of an elec-
tromechanical induction
disk relay. In this mode the
51P reset follows a slow
reset characteristic that de-
pends upon the duration of
the overcurrent condition
and the amount of load cur-
rent flowing after the event.
The reset equations are de-
scribed later in this section.
When the DPU1500R “Mul-
tiple Device Trip Mode” (see
“Multiple Device Trip Mode”
in Section 2) is enabled, the
51P reset characteristic de-
faults to the instantaneous
mode and cannot be set to
delayed. The reset mode applies to all time overcurrent elements in the DPU1500R.
Ground Time Overcurrent Element 51N (IN>)
The ground time overcurrent element, 51N, contained in the DPU1500R is calculated internally as the sum of the three
phace CT secondary currents or 3I
O
/
. Multiple time curves and time dials are available (see Table 1-2) to closely
coordinate with other devices in the system. The time-current curves for the DPU1500R are can be found later in this
section. User programmable curves are available depending on the DPU1500R model ordered (see Section 10 for
programmable curves). See Section 12 for help defining the unit model number. The 51N pickup, curve type, and time
dial are all set in the Primary, Alternate 1, and Alternate 2 settings groups. For the 51N element to operate the “Trip”
contact, it must be selected in the “Master Trip Output” mapping (see “Programmable Master Trip Contact” later in this
section). The 51N element is set by factory default to operate the “Trip” contact.
Table 1-1. 51P (3I>>) Characteristics
** See model number for applicability
*** Optional
See Table 5-1 for the 51P factory default settings
.
User Prog. Curve #3 *** 0 to 10 0.1
User Prog. Curve #2 *** 1 to 10 0.1
51P Parameter
Range/Curve
Time Dial
Increment
Pickup for 5 ampere model
1 to 12 amperes
0.1 ampere
Pickup for 1 ampere model
0.2 to 2.4 amperes
0.02 ampere
Time Overcurrent Curves **
ANSI
Inverse
1 to 10
0.1
Very Inverse
1 to 10
0.1
Extremely Inverse
1 to 10
0.1
Long Time Inverse
1 to 10
0.1
Long Time Very Inverse
1 to 10
0.1
Long Time Ext. Inverse
1 to 10
0.1
Short Time Inverse
1 to 10
0.1
Definite Time
0 to 10
0.1
Recloser Curve
1 to 10
0.1
IEC
Inverse 0.05 to 1.0
0.05
Very Inverse 0.05 to 1.0 0.05
Extremely Inverse 0.05 to 1.0 0.05
Long Time Inverse 0.05 to 1.0 0.05
User Prog. Curve #1 ***
1 to 10 0.1
