BECKWITH ELECTRIC M-3425A, Instruction Book

Page: 343 / 482

M‑3425A Instruction Book
6–56
81 Frequency (#1, #2, #3, #4)
VOLTAGE INPUTS:
Configuration V1
CURRENT INPUTS:
None
TEST SETTINGS:
Pickup P Hz (50.00 to 67.00)
50 Hz Relay (40.00 to 57.00)
Time Delay D Cycles (3 to 65,500)
50 Hz Relay
Programmed Outputs Z OUT (1 to 8)
Expanded I/O (9 to 23)

NOTE
: It would be efficient to disable the elements with the settings nearest to nominal frequency first
(testing over or underfrequency functions).
Test Setup:
1. Determine the Function 81 Frequency settings to be tested.
2. Enter the Function 81 Frequency 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. Set the three-phase voltages V
A
, V
B
, and V
C
to the
Nominal Voltage
(nominal frequency). The
Nominal
Voltage
value previously input to the relay is described in Section 4.2, Setup System and should be
recorded on Figure A-2, Setup System Record Form.
Pickup Test
:
1. Press and hold the
TARGET RESET
pushbutton, then slowly increase/decrease the Input Voltage
(V
A
, V
B
, and V
C
) Frequency until the
FREQUENCY/ROCOF 81/81R
LED illuminates or the function
status indicator on the
Monitor Function Status
screen indicates that the function has picked up.
The frequency level will be equal to
P
Hz ±0.02 Hz only if
P
is within 3 Hz of F
nom
, otherwise,

0.1 Hz.
2. Increase/decrease the Input Voltage (V
A
, V
B
, and V
C
) Frequency to nominal input frequency. The
OUTPUT
LED(s) will extinguish.
3. Press
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 (
P
+ or – 0.5) Hz and start timing. The contacts will close after
D
cycles within

2 cycles or
 1%, whichever is greater.