NI-9242 Specifications

Definitions

Warranted specifications describe the performance of a model under stated operating conditions and are covered by the model warranty.

Characteristics describe values that are relevant to the use of the model under stated operating conditions but are not covered by the model warranty.

  • Typical specifications describe the performance met by a majority of models.
  • Nominal specifications describe an attribute that is based on design, conformance testing, or supplemental testing.

Specifications are Typical unless otherwise noted.

Conditions

Specifications are valid for the range -40 °C to 70 °C unless otherwise noted.

NI-9242 Pinout



Table 1. Signal Descriptions
Signal Description
AI Analog input signal connection referenced to the Neutral signal
Neutral Referenced, single-ended analog input connection

Input Characteristics

Scaling coefficient

59,605 nV/LSB

Number of channels

4 analog input channels

ADC resolution

24 bits

Type of ADC

Delta-Sigma (with analog prefiltering)

Sampling mode

Simultaneous

Internal master timebase (fM)

Frequency

12.8 MHz

Accuracy

±100 ppm maximum

Data rate range (fs) using internal master timebase

Minimum

1.613 kS/s

Maximum

50 kS/s

Data rate range (fs) using external master timebase

Minimum

390.625 S/s

Maximum

51.2 kS/s

Data rates (fs)[1]1 The data rate must remain within the appropriate data rate range.

 fM÷ 256n
, n = 1, 2, …, 31

Input voltage range (AIx-to-Ground, Neutral-to-Ground, AIx-to-Neutral)

Typical

500 Vpk

Minimum

497 Vpk

Overvoltage withstand

500 Vrms continuous, 600 Vrms for 10 s

Surge withstand

8 kV (1.2 µs/50 µs)

Input coupling

DC

Input impedance, AIx-to-Ground and Neutral-to-Ground

1 MΩ

Table 2. DC and AC Accuracy
Measurement Conditions Percent of Reading (Gain Error) Percent of Range (Offset Error)[2]2 Range equals 354 V (250 Vrms × √2)
Calibrated Maximum, (-40 °C to 70 °C) 0.26% 0.14%
Typical, (23 °C±5 °C) 0.05% 0.022%
Note Accuracy specifications are valid for L-L, L-N and L-Earth measurements.
Input noise at 50 kS/s[3]3 The module returns L-N and N-Earth values only.

N-Earth and L-Earth

2.12 mVrms

L-N and L-L

3 mVrms

Note When measuring the amplitude of the fundamental frequency over one or several power cycles, the noise of the measurement reduces significantly (theoretically with the square root of the number of samples in the acquisition window).

Nonlinearity (at 25 °C)

20 ppm

Stability

Gain drift

12.1 ppm/°C

Offset drift

3.4 mV/°C

Post calibration gain match (channel-to-channel, maximum)

Up to 20 kHz

95 mdB

Up to 10 kHz

44 mdB

Up to 3.8 kHz

30 mdB

Phase mismatch (channel-to-channel)

0.138°/ kHz maximum

Phase mismatch (module-to-module, maximum)

0.138°/kHz + 360° * fin/ fM

Phase nonlinearity (fs = 50 kS/s)

0 kHz to 10 kHz

0.017° maximum

0 kHz to 20 kHz

0.034° maximum

Input delay

40

5512
/fs + 1.5 μs

Passband Frequency

0.453 * fs

Flatness

0 kHz to 20 kHz

±50 mdB maximum

0 kHz to 10 kHz

±20 mdB maximum

Negative phase sequence error at 50 Hz and 60 Hz
At 5% unbalance

Maximum

0.21%

Typical

0.09%

At 1% unbalance

Maximum

0.22%

Typical

0.1%

Zero phase sequence error at 50 Hz and 60 Hz
At 5% unbalance

Maximum

0.21%

Typical

0.09%

At 1% unbalance

Maximum

0.22%

Typical

0.1%

Stopband

Frequency

0.547 * fs

Rejection

-95 dB

Alias-free bandwidth

0.453 * fs

Anti-alias rejection (fs = 50 kS/s)

53 dB

-3 dB bandwidth (fs = 50 kS/s)

0.49 * fs

Crosstalk

60 Hz

-105 dB

1 kHz

-79 dB

CMRR (fin = 60 Hz)

-75 dB

SFDR (1 kHz, -60 dBFS)

-120 dB

Total Harmonic Distortion (THD), up to 1 kHz

-100 dB

Power Requirements

Power consumption from chassis

Active mode

332 mW maximum

Sleep mode

50 µW maximum

Thermal dissipation

Active mode

582 mW maximum

Sleep mode

250 mW maximum

Physical Characteristics

Screw-terminal wiring

Gauge

0.2 mm 2 to 3.0 mm2 (24 AWG to 12 AWG) copper conductor wire

Wire strip length

7 mm (0.28 in.) of insulation stripped from the end

Temperature rating

90 °C minimum

Torque for screw terminals

0.5 N · m to 0.6 N · m (4.4 lb · in. to 5.3 lb · in.)

Wires per screw terminal

One wire per screw terminal

Ferrules

0.25 mm2 to 2.5 mm2

Weight

150 g (5.3 oz)

Connector securement

Securement type

Screw flanges provided

Torque for screw flanges

0.5 N · m (4.42 lb · in.)

Safety Voltages

Connect only voltages that are within the following limits:

Maximum working voltage

250 V RMS L-N

400 V RMS L-L

Input voltage range (AIx-to-Ground, Neutral-to-Ground, AIx-to-Neutral)

Typical

500 V pk

Minimum

497 V pk

Overvoltage withstand

500 V RMS continuous

600 V RMS for 10 s

Maximum working voltage, channel-to earth ground

Continuous

250 Vrms, Measurement Category III

Withstand

8,000 V pk

Measurement Category III

Caution Do not connect the product to signals or use for measurements within Measurement Category IV.
Attention Ne pas connecter le produit à des signaux dans la catégorie de mesure IV et ne pas l'utiliser pour effectuer des mesures dans cette catégorie.

Measurement Category III is for measurements performed in the building installation at the distribution level. This category refers to measurements on hard-wired hardware such as hardware in fixed installations, distribution boards, and circuit breakers. Other examples are wiring, including cables, bus bars, junction boxes, switches, socket outlets in the fixed installation, and stationary motors with permanent connections to fixed installations.

Environmental Characteristics

Temperature

Operating

-40 °C to 70 °C

Storage

-40 °C to 85 °C

Humidity

Operating

10% RH to 90% RH, noncondensing

Storage

5% RH to 95% RH, noncondensing

Ingress protection

IP40

Pollution Degree

2

Maximum altitude

5,000 m

Shock and Vibration
Operating vibration

Random

5 g RMS, 10 Hz to 500 Hz

Sinusoidal

5 g, 10 Hz to 500 Hz

Operating shock

30 g, 11 ms half sine; 50 g, 3 ms half sine; 18 shocks at 6 orientations

To meet these shock and vibration specifications, you must panel mount the system.

Calibration

You can obtain the calibration certificate and information about calibration services for the NI-9242 at ni.com/calibration.

Calibration interval

1 year

1 The data rate must remain within the appropriate data rate range.

2 Range equals 354 V (250 Vrms × √2)

3 The module returns L-N and N-Earth values only.