Basler Electric BE1-64F - Manual (Page 9)

SECTION 1
• GENERAL INFORMATION
INTRODUCTION
The BE1-64F Ground Fault Relay detects and annunciates ground faults in the normally ungrounded field
circuit of a synchronous machine. A short-circuit in a synchronous machine’s field can often be prevented
by detecting and removing a ground fault before a second ground fault results in serious damage.
BE1-64F relays are compatible with continuous field voltages up to 600 Vdc and forcing voltages up to
750 Vdc for one minute. During reverse excitation (negative forcing), BE1-64F relays will withstand up to
1,200 Vdc for one minute.
Two sets of relay outputs and front panel indicators are provided for fault annunciation and tripping duty.
One set of output contacts, one front panel indicator, and a latching target indicator annunciate the
detection of a ground fault in the field winding. A second set of output contacts and a front panel indicator
annunciate the detection of lower than normal resistance across the field winding and ground.
Replacement of an ABB 64F with the BE1-64F is simplified because the panel cutout and drilling pattern
for the BE1-64F matches that of the ABB 64F.
SPECIFICATIONS
BE1-64F electrical and physical specifications are listed in the following paragraphs.
Operating Power
Voltage Range: 90 to 132 Vac
Frequency: 50/60 Hz
Burden: 150 mAac nominal, 200 mAac maximum
Terminals: A11 (N), A12 (L), A13 (GND)
Field Voltage Input
Continuous Rating: 600 Vdc
One Minute Forcing: 750 Vdc
One Minute Negative Forcing: 1,200 Vdc
Terminals:
A1 (F–), A3 (GND (CORE))
Block Input
Turn-On Threshold: 70 Vac,
±20 Vac
Operating Range: 90 to 132 Vac
Frequency: 50/60 Hz
Burden: 2 mAac
Terminals: A10 (L), A11 (N)
Operating Time
At 95% of Trip Value:
≤1 s
Sensitivity
Expressed as resistance from field negative lead to ground. See Figure 1-1 for the sensitivity
characteristic. In Figure 1-1, the dc fault voltage is the field voltage measured from the negative lead to
the faulted point in the field winding.
NOTE
To ensure protection against field grounds, the rotor iron must be grounded. Do
not rely on a ground path through the rotor bearings. Grounding must not be
installed where it bypasses the bearing insulation that prevents shaft currents.
Rotor grounding recommendations for a machine should be obtained from the
machine manufacturer.
9367200990 Rev B BE1-64F General Information 1-1