Model MW & MK series, designed for general performance measruing active & reactive power, accepts ac voltage & current signals with conversion to use a time division multiplier principle of an accurate detection the measured input power. The conversional process adopts pulse width modulation for voltage input & amplitude chopping modulation for current input to form a happed current pulse which as a multipling function of instant variables for input voltage & current. The integration of the instantaneous sample-conversion applied to MW series as a real power detection is able to measure a distorted sinusoidal wave with high harmonics even for a chopped SCR-conrolled waveform. The unit series include of the ratio input type & direct input type, the former defined to accept the secondary signal from CT & PT & to scale to primary reading display, the later calibrated to a reading to follow input. The designed specification , truely a real power system configuration, compliants ANSI-IEEE & DIN-IEC, VDE those standards with full protection for surge intrusion & accident input over to assure reliable operation.
1. Accuracy (23 + 3oC):
(1) 0.5% fs or 5 cts. which ever great:MWX, MWY,MWZ, MWQ,MKX,MKY,MKQ(3-3/4 digits).
(2) 0.25% fs + 1 count: MWX4,MWY4,MWZ4,MWQ4,MKY4,MKZ4,MKQ4 (4-1/2 digits).
2. Stability:
(1) Temperature coefficient < 60 ppm per degree C.
(2) Long term draft < 0.2% per year.
3. Digits & counts: 3-3/4 digits 3999 counts maximum, 4-1/2 digits 19999 counts maximum.
4. Display: 0.56" super rate LED.
5. Response time: sample rate 1 pf per sec typically.
6. Input over:
(1) Current input: 3 time rating-continuous, 10 time rating-30sec, 25 time rating-3 sec.
(2) Voltage input: maximum continuous 750V or 1.5 rating which ever great.
7. Frequency:
(1) Watt version norminal + 5Hz.
(2) Var version norminal + 0.5 hz < 0.2% change for 0.1 Hz deviated of center frequency.
8. Creat factor: normally < 3, MW.. series only.
9. Waveform: 3rd 30% for watt version only.
10. Dielectric strength:
(1) 2.5 KV rms / 1 minute, all terminals to reference ground (case).
(2) 2 KV rms / 1 minute, input terminals to power terminals.
11. Surge test: ANSI C37.90.1/1989, IEC 255-3 (1989).
12. Impulse voltage: (1) Impulse voltage 1.2 * 50 us 4 KV.
(2) Oscillation Wave 0.5us-100KHz 3KV or 1MHz-0.25 ms 2.5 KV.
13. Operating condition: operating temperature range -10 to 55oC, 0-99% RH non-condensed.
14. Storage condition: storage -25 to 70oC, 20-99% RH non-condensed.
15. Auxiliary power: AC + 15% < 6 VA, DC + 20% < 6 watts.