Basler Electric BE1-50/51B-235 - Manual (Page 11)

9252000898 Rev B BE1-50/51B-235/-236 General Information 1-1
SECTION 1 • GENERAL INFORMATION
INTRODUCTION
BE1-50/51B-235 and BE1-50/51B-236 protective relays are direct replacements for Westinghouse type
CO relays. The BE1-50/51B-235 has a 5-ampere current sensing input. The BE1-50/51B-236 has a
1-ampere current sensing input. Compatible Westinghouse model numbers are listed in Table 1-1.
Table 1-1. Westinghouse Relays Suitable for Direct Replacement
Catalog Number Curve Type
CO-2∗11∗1N Short Time
CO-5∗11∗1N Long Time
CO-6∗11∗1N Definite
CO-7∗11∗1N Moderately Inverse
CO-8∗11∗1N Inverse
CO-9∗11∗1N Very Inverse
CO-11∗11∗1N Extremely Inverse
∗ Any digit covering all pickup ranges except 50 Hz models.
To replace an existing Westinghouse type CO, perform the following steps.
1. Select the desired relay settings on your new BE1-50/51B-235 or BE1-50/51B-236 relay.
2. Remove the existing ABB relay cradle.
3. Insert the new relay cradle.
4. Close the knife-blade switches.
5. Install the new Basler Electric cover and secure with the captive thumbnut.
BE1-50/51B-235 and BE1-50/51B-236 relays are self-powered, compatible with 50 or 60 Hz power
systems, and have three protection elements: one time overcurrent (51) element and two instantaneous
overcurrent (50) elements. The 51 element offers timing characteristic curves similar to those used by GE
IAC relays.
FEATURES
A wide range of pickup settings and front panel selectable time characteristics permit applications
involving coordination with fuses, reclosers, cold load pickup, motor starting, and fixed time requirements.
In addition, an integrating reset function is available to simulate the disk reset of electromechanical relays.
BE1-50/51B-235 and BE1-50/51B-236 overcurrent relays have the following standard features.
• Independent time and instantaneous elements
• A secure method to manually trip the breaker at the relay front panel
• Direct reading front panel controls
• Minimum pickup setting for safety during installation
• Time characteristics extend to a pickup multiple of 40
• Rugged draw-out construction
• Gravity latching targets retain indication without power
• Built-in accuracy eliminates internal adjustments
• Minimum transient overreach
• Field selectable characteristic curve selection similar to either GE IAC or Westinghouse CO type
curves
• Field selectable instantaneous or integrating reset
• Field selectable 50 or 60 Hz operation
• Field selectable 0.0 or 0.1 second, fixed, instantaneous delay
Internal switches provide for selecting system-operating frequencies of 50 or 60 Hz, instantaneous
element delays of 0.0 or 0.1 second, characteristic curve group selection for either GE IAC or
Westinghouse CO type curves, and instantaneous or integrating reset characteristics. Switch location and
description is provided in Section 2.