BE1-50/51M-222 Testing
5-6
SETTING THE RELAY
Select the desired relay settings before putting the relay into service. Changing pickup current settings while
the relay is in service may cause tripping.
PERIODIC TESTS
General
All relays should be tested periodically to identify and correct any problems that are found.
Single phase relays such as the BE1-50/51M-222 are normally used in groups of four (three phase and
ground) on the protected circuit. Only three are required at any one time to provide complete protection.
The fourth one assures that protection is maintained even if one relay failed.
This protection scheme also allows one unit at a time to be withdrawn for testing purposes without losing
protection during the test. Refer to Figures 5-1 and 5-2 for recommended test setups.
Periodic Test
Periodic testing should consist of the following procedures.
Step 1. Verify that the instantaneous pickup is within ±2% of the value set on the dials. Pickup occurs when
the INST output contacts close.
Step 2. Verify that the time pickup is within ±2% of the value set on the dials. Pickup occurs when the LED
turns ON.
Step 3. Verify that the time to trip for the curve and time dial settings at a multiple of six is the same as the
time given on the characteristic curve. Refer to Section 1 for the characteristics curves.
Step 4. Verify that the time to trip for the instantaneous element at a pickup multiple of 2 is not greater than
the time given on the instantaneous characteristic curve. Refer to Section 1 for the instantaneous
characteristic curve.
Step 5. Verify that the 51 AUX contacts close when the time overcurrent element trips.
Step 6. Verify that the targets operate with one ac ampere of trip current in the trip circuits and that they can
be reset using the RESET LEVER.
This completes the periodic test.
Summary of Contents for BE1-50/51M-222
Page 29: ...BE1 50 51M 222 Installation 4 2 Figure 4 1 Outline Dimensions C1 Case ...
Page 30: ...BE1 50 51M 222 Installation 4 3 Figure 4 2 Panel Drilling Diagram C1 Case ...
Page 32: ...BE1 50 51M 222 Installation 4 5 Figure 4 4 DC Control Connections ...
Page 33: ...BE1 50 51M 222 Installation 4 6 Figure 4 5 BE1 50 51M 222 Overcurrent Relay Rear View ...