ACI Energy Meters

| Overview

ACI provides cost efficient energy monitoring devices that are flexible, affordable, and easy to integrate.  There are several options to choose from:

1. KW350
   • Monitors up to 3 circuits as high as 6000 amps
   • Powered by 100-415 VAC, or 100 - 300 VDC.
   • Power consumption <2W
   • Rated for up to 400VAC Line to Neutral or 690VAC Line to Line
   • Configurable for Bacnet MS/TP or Modbus RTU
   • DIN Rail mounted
   • Measures real-time, true RMS of voltage, current, power, frequency and power factor.
   • Two models available, one which supports 333mV and one that supports Rogowski Coils (must select proper model based on CT type)
2. KW1850
   • Monitors up to 18 circuits and has 18 digital inputs to measure energy metering via pulse counting or dry node.
   • Powered by 100-415 VAC, or 100-300 VDC
   • Power Consumption 5W
   • Rated for up to 400 VAC Line to Neutral or 690 VAC Line to Line
   • Configurable for Bacnet MS/TP, Bacnet IP, or Modbus RTU
   • DIN Rail mounted
   • Measures real time, true RMS of voltage, current, power, frequency, harmonics, phase angle, demand, unbalance factor, running time and power factor
   • (One model, but cannot mix 333mV and Rogowski Coils on the same meter)

75F Provides both variations in an NEMA 4X/IP66, UL508A Listed enclosure.  The enclosure comes internally prewired with all required fuses and terminals.  Because of the tamper-proof design, these enclosures are approved for revenue applications.

The meters are also easily integrated into Facilisight with data displayed in PAM.

| How to Scope/Price Meters

To properly build a scope and BOM for this type of request, it's imperative to have the following information:

• Service Type (Single phase, 3-phase single wire, 3-phase four wire (WYE), 3-phase three wire (Delta)
• Type of load being monitored
• Count of circuits
• Amp ratings of the CTs needed (If not customer provided, see below how to calculate)
• If the KW1850 is selected, accurate single-line documents and panel schedules are mandatory

The strong preference and recommendation is to monitor each circuit individually.  However, you may use one single CT to measure several circuits as long as they're powered by the same source and are on the same phase.

Example: A request to monitor HVAC load, Lighting load, Workstation Plug load, and Kitchen Appliance loads on a single tenant floor.

HVAC Load

• 8 RTUs, all 3-phase 480VAC.  5 RTUs have 50a breakers, 1 has a 100a breaker, and 2 have 200a breakers.  These are all in the same panel, which is dedicated to the units.
  • • Select 3 CTs (one for each phase)
    • Add the maximum rated current of each phase and select a CT with a current rating equal to or larger than the highest phase current.  For this example, you'd select 800a CTs since the max rating is 750a.

Lighting Load

• • The lighting on the floor is in 4 separate panels.  Part of the lighting is 277 VAC in one panel, and the rest is 120/208 VAC in 3 others.  The 277/480 panel is fed from the same bus plug as the HVAC.  The 120/208 panels are powered by a transformer coming from a breaker on the same 277/408 panel mentioned earlier.
    • Select 3 CTs (one for each phase)
    • Match the CTs to the rating of the main breaker on the 277/480 panel.

Plug Load

• • Plug load is all 120/208 in 4 panels.  2 panels are fed from a transformer on the east side of the floor, 2 are fed from a transformer on the west side of the floor.
  • The panels with plug loads are also shared with other types of loads that will not be monitored. 
    • Select 3 CTs for each panel.  Size as described above.

Kitchen Appliance Load

• • Kitchen appliances are all 120/208 and located in the same panel.  The panel is shared with plug loads from the rest of the space.  There are 6 total circuits only on A or C phase.
    • Add the maximum rated current of each phase in each panel and select a CT with a current rating equal to or the next highest phase current.  Select 2 CTs.

Final Quote

• (1) KW1850 meter with 6 CTs.
  • The HVAC and Lighting can be monitored from the same KW1850 meter since they are fed from the same power source.  Also, since the 120/208 lighting is being fed from the 277/480 panel and are all dedicated to lighting, the lighting load can be monitored through the main 277/480 panel if lighting does not need to be broken out more granularly.
• (2) KW1850 meters with 14 total CTs
  
  • The panels on the west side of the floor would get (1) KW1850 meter and 6 total CTs.
  • The panels on the east side of the floor would get (1) KW1850 meter and 8 total CTs (6 for lighting, 2 for appliances)

Design

For the HVAC/Lighting Meter

1. Bring power for phases A,B,C from the bus plug, the HVAC panel, or the lighting panel to the KW1850 meter for the HVAC and Lighting.  The circuit does not have to be on the main or have a dedicated circuit.
2. For both panels, place the CTs on the incoming phase A, B, C wires.
3. Use channels 1, 2, and 3 for the HVAC CTs.  Use channels 4, 5 and 6 for the lighting CTs. 
4. Channels 1 and 4 need to be Phase A, 2 and 5 need to be Phase B, 3 and 6 need to be Phase C.

For the West Plug Load Meter

1. Bring power for phases A,B,C from one of the 120/208 panels to the KW1850 dedicated to plug loads.  This must be from one of the two panels that serve the loads being monitored.
2. Since these panels are shared with other loads, wrap the CT only around the wires that feed the plug loads.
3. Use channels 1, 2, 3 for the CTs coming from the first panel and channels 4, 5, 6 from the second panel (phasing per channel as described above).

For the East Plug/Kitchen Appliance Load Meter

1.  Bring power for phases A,B,C from one of the 120/208 panels to the KW1850 dedicated to plug and appliance loads.  This must be from one of the two panels that serve the loads being monitored.
2. Since these panels are shared with other loads, wrap the CT only around the wires that feed the plug loads.
3. Use channels 1, 2, 3 for the CTs coming from the first panel without appliance load.  Use channels  4, 5, 6 for the plug load circuits on the second panel.  Use channels 7 and 9 for the appliance CTs (skip 8 since appliances are only fed by Phase A or Phase C).