MK233A

Features
• Microprocessor based numerical relay • Definite time for low-set and high-set
• Current measurement based on • Non-volatile fault value recording
fundamental frequency
• Programmable relay outputs
• Three-phase, low-set overcurrent • Five selectable IDMT characteristic curves

MK233A Overcurrent Relay

• Three-phase, high-set overcurrent • Complies with IEC 60255-26 standard
• Local display of measured and set values

Technical Data
RATINGS
Rated current ( In ) : 5A
Rated frequency : 50 or 60 Hz
Burden : < 0.3 VA at In
Thermal withstand : 4 x In continuous

AUXILIARY SUPPLY
Model MK233A-240A (6) : 198 ~ 265 V AC
Model MK233A-110A (6) : 94 ~ 127 V AC
Supply frequency : 50 or 60 Hz
VA rating : 3 VA typical

SETTING RANGES
Low-set ( I > ) : 0.5 A to 6.0 A, step 0.05 A / 10% to 120%, step 1%
Low-set time multiplier ( kt > ) : 0.05 to 1.0, step 0.01
Low-set definite time (t >) : 0.05 to 99 sec, step 0.01 (0.05 to 1.0) / 0.1 (1.1 to 99)
High-set ( I >> ) : 0.5 A to 99.9 A or disable, step 0.10 A / 10% to 1998%, step 2%
High-set delay time ( t >> ) : 0.05 sec to 2.5 sec, step 0.01

ACCURACY
Protection thresholds : ± 5%
Time delay : ± 5% with a minimum of 50 ms

CONTACTS ( R1 & R2 )
Contact arrangement : Change-over
Contact rating : 5 A, 250 V AC ( cosϕ = 1 )
Contact material : Silver alloy
Expected electrical life : 100,000 operations at rated current
Expected mechanical life : 5 x 106 operations

INDICATORS
Auxiliary supply : Green indicator
Pick-up : Red indicator
Trip : 7-segment display and red indicators

MECHANICAL
Mounting : Panel mounting
Front panel : Standard DIN 96 mm x 96 mm
Approximate weight : 0.7 kg

ENVIRONMENTAL CONDITIONS
Temperature : -5˚C to +55˚C
Humidity : 56 days at 93% RH and 40˚C non-condensing
 NORMAL INVERSE VERY INVERSE LONG TIME INVERSE
MK233A Overcurrent Relay

TYPICAL APPLICATION DIAGRAM

Aux
L N MK 233A
NO NC COM COM NC NO
1 2 3 4 5 6 7 8

EXTREMELY INVERSE NORMAL INVERSE 1.3/10

R1 R2

9 10 11 12 13 14 15 16

L1
L2
L3
N

CASE DIMENSIONS

96 mm
96 mm

Front

110 mm
100 mm

Side

Ordering Information
91.0 ± 0.5 mm
MODEL DESCRIPTION
MK233A - 240A For 50 Hz system, auxiliary voltage198 ~ 265 V AC
91.0 ± 0.5 mm

MK233A - 110A For 50 Hz system, auxiliary voltage 94 ~ 127 V AC

MK233A - 240A6 For 60 Hz system, auxiliary voltage198 ~ 265 V AC Panel Cutout
MK233A -110A6 For 60 Hz system, auxiliary voltage 94 ~ 127 V AC