BECKWITH ELECTRIC M-3425A, Instruction Book

Page: 295 / 482

M‑3425A Instruction Book
6–8
21 Phase Distance (#1, #2 or #3)
VOLTAGE INPUTS:
Configuration V1
CURRENT INPUTS:
Configuration C1
TEST SETTINGS:
Diameter P Ohms (0.1 to 100)
1 Amp CT Rating (0.5 to 500.0)
Offset O Ohms (–100 to 100)
1 Amp CT Rating (–500.0 to 500.0)
Impedance Angle A Degrees (0 to 90)
Time Delay D Cycles (1 to 8160)
Programmed Outputs Z Output (1 to 8)
Expanded I/O (9 to 23)
VT Configuration Line-Ground or Line-Line

NOTE:
It would be efficient to disable the element with the higher “reach” (Diameter plus Offset) setting
first ( lower current ), and test the lower reach setting operation, since the higher reach setting
operation can be tested without disabling the lower setting.
Test Setup:
1. Determine the Function 21 Phase Distance settings to be tested.
2. Enter the Function 21 Phase Distance settings to be tested utilizing either the HMI or IPScom
®
Communications Software.
3. Disable all other functions prior to testing. Refer to Section 4.4 System Setpoints, for details that
describe disabling/enabling functions.
4. Connect test voltage inputs as shown in Figure 6-1, Voltage Inputs: Configuration V1.
5. Connect test current inputs as shown in Figure 6-3, Current Inputs: Configuration C1.
6. The level of current at which pickup operation is to be expected for an individual setting is determined
as follows:
a. Define “reach” as
R
ohms = (
P
ohms +
O
ohms) [
O
, usually set at zero ohms].
b. For Line-Ground configuration, define “current” as
I
= ((Selected Voltage)
I R
ohms). The voltage
level may be selected based on the desired test current level. For Line-Line configuration, define
“current” as
I
= ((Selected Voltage/
S
3)
I R
ohms).
Pickup Test
:
1. Set the three-phase voltages to the Selected Voltage value from Step 6b above.
2. Set the phase angle between the voltage and current inputs at (
A
) degrees from settings above (for
Line-Line configuration, set the phase angle at (
A
–30°).
3. Press and hold the
TARGET RESET
pushbutton, then slowly increase the three-phase input currents
until the
21 PHASE DISTANCE
LED illuminates, or the pickup indicator illuminates on the IPScom
Function Status screen.
The level at which the
21 PHASE DISTANCE
actuates should be equal to
I
calculated in Step 6 with
the resulting impedance

0.1 ohms or 5%.
4. Release the
TARGET RESET
pushbutton, then decrease the three-phase input currents. The
assigned
OUTPUT
LEDs will extinguish.
5. Press the
TARGET RESET
pushbutton to reset targets.
Time Test
:
1. Connect a timer to output contacts
(Z)
so that the timer stops timing when the contacts
(Z)
close.
2. Apply approximately 110% of the current (
I
) found in Step 6, and start timing. The contacts will close
after
D
cycles within  1 cycle or  1%.