WEG UBW120, Руководство пользователя

Страница: 3 / 16

WEG Molded Case Circuit Breakers - User’s Manual
www.weg.net
WEG Molded Case Circuit Breakers - User’s Manual 3
Trip unit functions
Digitrip RMS 310+ trip unit
LS LSI
Long time Adjustable Ampere rating with adjustable long delay • •
Short time
Adjustable short time pick-up with short time delay l²t ramp •
Adjustable short time delay
1)
with adjustable short time pick-up •
Instantaneous Fixed instantaneous (override)
2)
• •
Table 1: electronic (Digitrip 310+) trip unit types
Notes: 1) Using trip unit with adjustable delay (LSI), instantaneous pick-up is achieved when the lowest time delay
setting (l) is selected for non-arms trip units.
2) Override setting fixed at frame withstand rating.
Trip functions Range/setting description
2)
Ampere rating adjustable
with IR switch
Trip unit ampere rating (IR)
1200 Amp
800 Amp
Short delay pick-up (adjustable) In multiples of amperes (I
n
) with marks at 2-3-4-5-6-7-8-9x
Short delay time
(adjustable)
I²t ramp configuration
Short delay time
(adjustable)
Flat response with time delay settings at Instantaneous
120 ms and 300 ms
Ground fault
Pick-up (adjustable)
Trip unit Ampere rating Trip unit setting
1200 Amp
800 Amp
Ground fault time delay Flat response with time settings of: Inst, 120 ms and 300 ms
Table 2: electronic (Digitrip 310+ trip unit function and rating sensing
Notes: 1) Occurs with short delay time adjustment set at 1.
2) The molded case switch has a fixed instantaneous setting.
The UBW1200 Trip Units are AC only devices that employ microprocessor based
technology that provides true RMS current sensing means for proper correlation with
thermal characteristics of conductors and equipment. The primary function of the trip unit
is circuit protection. This is achieved by analyzing the secondary current signal received
from the circuit breaker current sensors and initiating trip signals to the circuit breaker shunt
trip when pre-set current levels and time delay setting are exceeded. Low level ground
fault protection with an adjustable time delay is supplied when appropriate trip types are
selected.
In open air at 40 ºC (104 ºF), a UBW1200 circuit breaker with a 310+ trip unit will carry
continuously up to 1200 Amperes without exceeding a 50 ºC (122 ºF) rise at the terminals.
The calibration of the trip unit is insensitive to ambient temperatures over a range of
-20 to +55 ºC (-4 to 131 ºF). However, the trip unit contains thermal temperature protective
circuitry that initiates a trip operation for self-protection if the internal ambient temperature at
the printed circuit board (PCB) reaches approximately 90 ºC. For ambient conditions above
40 ºC (104 ºF), derating of the circuit breaker should be considered to avoid exceeding a
safe terminal temperature operation range. Consult WEG for recommendations.