GE t60 Instruction Manual page 190

5.5 GROUPED ELEMENTS
The element has a linear reset characteristic. The reset time can be programmed to match the cooling characteristics of the
protected equipment. The element will fully reset from the trip threshold in
may be used as an instantaneous element with no intentional time delay or as a Definite or Inverse timed element.
The characteristics of the inverse curves are shown below.
• DEFINITE TIME: T(sec.) = TD Multiplier. For example, setting the TD Multiplier set to 20 means a time delay of 20 sec-
onds to operate, when above the Volts/Hz pickup setting. Instantaneous operation can be obtained the same way by
setting the TD Multiplier to "0".
• INVERSE CURVE A:
The curve for the Volts/Hertz Inverse Curve A shape is
derived from the formula:
TDM
------------------------------------------------ - when
T =
V
  Pickup
⁄
--- -
 
F
where: T = Operating Time
TDM = Time Delay Multiplier (delay in sec.)
V = fundamental RMS value of voltage (pu)
F = frequency of voltage signal (pu)
Pickup = volts-per-hertz pickup setpoint (pu)
• INVERSE CURVE B:
5
The curve for the Volts/Hertz Inverse Curve B shape is
derived from the formula:
TDM
---------------------------------------------- when
T =
V
  Pickup
⁄
--- -
 
F
where: T = Operating Time
TDM = Time Delay Multiplier (delay in sec.)
V = fundamental RMS value of voltage (pu)
F = frequency of voltage signal (pu)
Pickup = volts-per-hertz pickup setpoint (pu)
• INVERSE CURVE C:
The curve for the Volts/Hertz Inverse Curve C shape is
derived from the formula:
TDM
---------------------------------------------------- - when
T =
V
  Pickup
⁄
--- -
 
F
where: T = Operating Time
TDM = Time Delay Multiplier (delay in sec.)
V = fundamental RMS value of voltage (pu)
F = frequency of voltage signal (pu)
Pickup = volts-per-hertz pickup setpoint (pu)
5-112
V
--- - >
Pickup
F
2
– 1
V
--- - >
Pickup
F
– 1
V
--- - >
Pickup
F
0.5
– 1
T60 Transformer Management Relay
VOLTS/HZ T-RESET
1000
100
(EQ 5.20)
10
1
0.1
0.01
1.00
1000
100
(EQ 5.21)
10
1
0.1
1.00
10000
1000
(EQ 5.22)
100
10
1
0.1
1.00
5 SETTINGS
seconds. The V/Hz element
1.20 1.40 1.60 1.80
Multiples of Volts/Hertz Pickup
1.20 1.40 1.60 1.80
Multiples of Volts/Hertz Pickup
1.20 1.40 1.60 1.80
Multiples of Voltz/Hertz Pickup
GE Multilin
Time
Delay
Setting
10
3
1
0.3
0.1
2.00
Time
Delay
Setting
10
3
1
0.3
0.1
2.00
Time
Delay
Setting
10
3
1
0.3
0.1
2.00