| Battery Type | AA | 
| AC Voltage Measurement | 
| Range | 500 volt | 
| Resolution | 0.1 volt | 
| Accuracy 45-66 Hz | 0.8 percent + 3 | 
| Input Impedance | 360 kΩ | 
| Overload Protection | 660 volt RMS | 
| Continuity Testing (RLO) | 
| Range (Autoranging) | 20/200/2000 Ω | 
| Resolution | 0.01/0.1/1 Ω | 
| Open Circuit Voltage | >4 volt | 
| Insulation Resistance Measurement (RISO) | 
| Test Voltages | 50, 100, 250, 500, 1000 volt | 
| The accuracy of Test Voltage (at rated test current) | +10 percent, -0 percent | 
| Test Voltage | 50 volt 100 volt
 250 volt
 500 volt
 1000 volt
 | 
| Insulation resistance range | 20/50 MΩ 20/100 MΩ
 20/200 MΩ
 20/200/500 MΩ
 20/200/1000 MΩ
 | 
| Resolution | 0.01/0.1 MΩ 0.01/0.1 MΩ
 0.01/0.1 MΩ
 0.01/0.1/1 MΩ
 0.01/0.1/1 MΩ
 | 
| Test Current | 1 mA at 50 kΩ 1 mA at 100 kΩ
 1 mA at 250 kΩ
 1 mA at 500 kΩ
 1 mA at 1 MΩ
 | 
| Loop and Line Impedance (ZI) | 
| Range | 10/0.001 Ω/High Current mΩ Mode | 
| Resolution | 0.01/0.1/1 Ω | 
| Prospective earth fault current, PSC test | 
| Range | 1000 Amps/10 kA (50 kA) | 
| Resolution | 1 Amps/0.1 kA | 
| Computation | Prospective earth fault current (PEFC) or Prospective short circuit current (PSC) determined by dividing measured mains voltage by measured loop (L-PE) resistance or line (L-N) resistance, respectively. | 
| RCD Testing, RCD Types Tested | 
| RCD Type | AC¹ G²,S³
 | 
| Model 1663 | A4, AC¹, G²,S³ | 
| Notes | Responds to AC General, no delay
 Time delay
 Responds to pulsed signal
 Responds to smooth DC signal
 | 
| Tripping speed test (ΔT) | 
| Current settings¹ | 10, 30, 100, 300, 500, 1000 mA – VAR 10-30-100 mA
 | 
| Multiplier | x ½, x 1 x 5
 | 
| Measurement Range | RCD Type G | 310 ms 50 ms
 | 
| RCD Type S | 510 ms 160 ms
 | 
| Notes | 1000 mA Type AC only 700 mA maximum type A in VAR mode
 VAR mode not available for type B
 | 
| RCD/FI-Tripping Current Measurement/Ramp Test (IΔN) | 
| Current Range | 30 percent to 110 percent of RCD Rated Current | 
| Step Size | 10 percent of IΔN² | 
| Dwell Time | Type G | 300 ms/step | 
| Type S | 500 ms/step | 
| Measurement Accuracy | ±5% | 
| Specified Trip Current Ranges (EN 61008-1) | 50 to 100 percent for Type AC 35 to 140 percent for Type A (>10 mA)
 35 to 200 percent for Type A (≤10 mA)
 50 to 200 percent for Type B
 | 
| Notes | 30 to 150 percent for Type A IΔN > 10 mA 30 to 210 percent for Type A IΔN = 10 mA
 20 to 210 percent for Type B
 | 
| Earth Resistance Test (RE) | 
| Range | 200/2000 Ω | 
| Resolution | 0.1/1Ω | 
| Frequency | 128 Hz | 
| Output Voltage | 25 volt | 
| Phase Sequence Indication | 
| Icon | Phase Sequence Indicator is Active. | 
| Size | 100 x 250 x 125 mm | 
| Weight | 1.3 Kg |