Power System Wiring; Residual Current Measurement - Siemens US2:9810T24V User Manual

Installation and commissioning
HAZARD OF ELECTRIC SHOCK, EXPLOSION OR ARC FLASH
Failure to follow these instructions will result in death or serious injury.
• Apply appropriate Personal Protective Equipment (PPE) and follow safe electrical work
practices. See NFPA 70E, CSA Z462 or other local standards.
• Turn off all power supplying this device and the equipment in which it is installed before
working on or in the equipment.
• Always use a properly rated voltage sensing device to confirm that all power is off.
• Do not use the data from the meter to confirm power is off.
• Do not exceed the maximum ratings of this device.
• Do not short secondary terminals of Voltage Transformer (VT).
• Do not open secondary terminals of Current Transformer (CT).
• Ground secondary circuit of CTs.
• Use only Low Power Current Transformers (LPCTs) that are approved for use with this
device.
• Do not connect CT secondary signals to meter low voltage LPCT terminals.
• Do not install CTs or LPCTs in equipment where they exceed 75% of the wiring space of any
cross-sectional area in the equipment.
• Do not install CTs or LPCTs in areas where ventilation openings may be blocked or in areas
of breaker arc venting.
• Do not install CTs or LPCTs using Class 2 wiring methods or connect to Class 2 equipment.
See NFPA 70.
• Secure CT or LPCT secondary conductors to ensure they do not contact live circuits.
• Assume communications and I/O wiring are hazardous live until determined otherwise.
• Replace all devices, doors and covers before turning on power to this equipment.

Power system wiring

You can connect the meter's voltage inputs directly to the phase voltage lines of the power system
if the power system's line-to-line or line-to-neutral voltages do not exceed the meter's direct
connect maximum voltage limits.
The maximum voltage allowed for direct connection may be lower than the manufacturer-
specified limits, depending on the local electrical codes and regulations.
If your system voltage is greater than the specified direct connect maximum voltage, you must
use voltage (potential) transformers (VTs/PTs) to step down the voltages.

Residual current measurement

The meter can calculate or measure the residual current, depending on how the inputs are wired.
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9810 series - User manual
7EN05-0390-08