Standard Features For Rel302 (Pilot); Optional Features For The Non-Pilot Rel301 And Pilot Rel302; Rel301/302 Construction; Rel301/302 Outer Chassis - ABB REL 301 Instruction Leaflet

Standard Features for REL302 (Pilot)

1.2.2
• All features listed as standard for the REL301 are also standard in the REL302
• Independent pilot zone phase and ground distance units
• Permissive Overreach Transfer Trip (POTT) /Simplified Unblocking Logic
• Permissive Underreach Transfer Trip Logic
• Directional Comparison Blocking Logic
• POTT or Simplified Unblocking Weakfeed Terminal Logic
• Instantaneous Forward Directional Overcurrent Function for High Resistance Ground Fault
Supplement to Overreach Pilot
• Instantaneous Reverse Directional Overcurrent Ground Function for Carrier Start on Block-
ing Scheme
• Low voltage pickup setting for weakfeed logic and close into fault trip
• Reclose Block on Breaker Failure Squelch
• 3-Terminal Line Application
1.2.3

Optional Features for the Non-Pilot REL301 and Pilot REL302

• Man Machine Interface (LCD Display)
Review or update all settings
Review two most recent
Line voltage, current and phase angle monitoring
• RS-232C front communications port
• 5 programmable contact outputs
• Reclosing with or without Synchronism/Voltage Check (See I.L. 40-386.12 for details)
• Up to 4 reclose attempts
• Instantaneous or time delay (each reclose attempt)
• Reset Timer
• Live-Line Dead-Bus/Dead-Line Live-Bus logic
• Synchronism check
• 120 Volt phase-to-phase synchronism voltage input option
1. 3.

REL301/302 CONSTRUCTION

All of the relay circuitry, with the exception of the first-line surge protection, is mounted on the
inner chassis, to which the front panel is attached. The outer chassis has a backplane, which is
a receptacle for all external connections, including a communication interface. The integral
FT-10 switches permit convenient and safe disconnection of trip, ac and dc input circuits, and
provide for injection of test signals.
1.3.1

REL301/302 Outer Chassis

This is an FT-42 case, where all the input/output signals are surge protected. All external con-
nections are made through the rear of the case (except optional front communications port).
The outer chassis (Figure 1-4) consists of 2 surge protection modules, a backplane surge pro-
tection module, a metal case, FT-switches and a communication interface consisting of a Prod-
uct Operated Network Interface (PONI) which is either a NET (INCOM
PONI mounted on the inside of the case on the backplane module.
I.L. 40-386.4
®
) PONI or RS (RS-232C)
1-3