ABB Relion 650 Series Technical Manual page 204

Section 6
Current protection
Table 109: LPTTR (26) Non group settings (basic)
Name Values (Range)
GlobalBaseSel 1 - 6
6.9.6 Monitored data
Table 110: LPTTR (26) Monitored data
Name
TTRIP
TENRECL
TEMP
TEMPAMB
6.9.7 Operation principle
The sampled analog phase currents are pre-processed and for each phase current the RMS value is
derived. These phase current values are fed to the thermal overload protection, one time constant
function LPTTR (26).
From the largest of the three-phase currents a final temperature is calculated according to the
expression:
Q =
final
EQUATION1167 V1 EN-US
where:
I
I
ref
T
ref
If this temperature is larger than the set operate temperature level,
signal is activated.
The actual temperature at the actual execution cycle is calculated as:
198
Unit
-
Type
INTEGER
INTEGER
REAL
REAL
2
æ ö
I
×
ç ÷ T
ç ÷
ref
I
è ø
ref
is the largest phase current,
is a given reference current and
is steady state temperature corresponding to I
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Step Default
1 1
Values (Range) Unit
- -
- -
- -
- -
ref
1MRK 506 326-UUS B
Description
Selection of one of the Global Base Value
groups
Description
Estimated time to trip (in min)
Estimated time to reset of lockout (in min)
Calculated temperature of the device
Ambient temperature used in the
calculations
TripTemp , a PICKUP output
Line distance protection REL650
Technical manual
PID-2593-MONITOREDDATA v5
M12018-3 v4
(Equation 35)