Toshiba GR200 Series Instruction Manual page 355

Drop-off and pick-up characteristic
2.25.1
Figure 2.25-1 shows the UVS characteristic as hatched area with concentric circles. The pick-
up threshold voltage (PU) is represented the outer circle; the drop-off voltage point (DO) is
represented the dotted circle. The PU voltage of the UVS1 element is set using [UVS1]. The
DO voltage of the UVS1 element is set using [UVS1-DPR].
The inner circle shows the area in which the UVS function is blocked when the value of
the block voltage is set for [UVSBLK]. Setting [TUVSBLK] is also provided so that the user can
delay blocking the UVS1 and UVS2 elements using the setting.
Time characteristic
2.25.2
The UVS element has the relationship between an input voltage and an operation time; the
relationship is divided into two time characteristics: (i) the definite time (DT) and (ii) the
inverse definite minimum time (IDMT).
Definite time characteristic (DT)
(i)
Setting pick-up operation
The user is required to set DT for scheme switch [UVS1-Timer] when the UVS1 element should
run in the DT characteristic. The UVS1 element has a delay timer for the operation; the user
can set a delay time using setting [TUVS1]. The user can find the delay timer in the UVS
function logic. (See section 2.25.4)
Setting drop-off operation
Resetting the UVS1 element is performed instantly when a voltage exceeds over the drop-off
voltage.
Inverse definite minimum time (IDMT) characteristic
(ii)
To operate the inverse definite minimum time (IDMT), set scheme switch [UVS1-Timer] IDMT.
Pickup
Figure 2.25-1 UVS1 element characteristic
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Drop-off
V
V
o
UVS block
6F2S1914 (0.49)
GRL200 (Soft 033 & 037)