14
Maximum Power Supply Voltage Range:
-20% to +15% of nominal (see table above). For the
3D-240 service, this is -20% of 208 Vac (166 Vac) to +15% of 240 Vac (276 Vac).
Operating Frequencies:
50/60 Hz
Measurement Category:
CAT III
Measurement category III is for measurements performed in the building installation or on the
load side of the main service breaker. Examples are measurements on distribution boards,
circuit-breakers, wiring, including cables, bus-bars, junction boxes, switches, socket-outlets in
the fixed installation, and equipment for industrial use and some other equipment, for example,
stationary motors with permanent connection to the fixed installation.
The line voltage measurement terminals on the meter are rated for the following CAT III voltages
(these ratings appear on the front label):
Meter Service Type
CAT III Voltage Rating
3Y-208
3D-240
240 Vac
3Y-400
3D-400
400 Vac
3Y-480
3D-480
480 Vac
3Y-600
600 Vac
Table 4: WattNode CAT III Ratings
Current Transformer Inputs:
Nominal Input Voltage (At CT Rated Current):
0.33333 Vac RMS
Absolute Maximum Input Voltage:
5.0 Vac RMS
Input Impedance at 50/60 Hz:
23 kΩ
5.4 Thermistor Input
The WattNode BACnet is available with
Option TM1
, which provides hardware and firmware
updates to support connection of a thermistor between the
C
and
X
pins on the black four-position
connector. The firmware for
Option TM1
is not BTL (BACnet Testing Laboratories) certified; how-
ever, it is based on BTL certified firmware.
Thermistor Type:
10k, US Sensor J-curve
Temperature Accuracy:
±3°C, not including thermistor errors
Temperature Resolution:
better than 1°C from -50°C to 150°C
Response Time:
<= 2 seconds (not including thermistor response time)
Temperature Measurement Range:
-50°C to 150°C
5.5 EIA RS-485 Interface
RS-485 Output Isolation:
4500 Vac RMS
Driver Output:
●
Voltage (Open Circuit)
: ±6 Vdc maximum
●
Voltage (54 Ω load)
: ±1.5 Vdc minimum
●
Current (54 Ω load)
: ±60 mA typical
●
Rise Time (54 Ω || 50 pF load)
: 900 nS typical
Receiver:
●
Common-Mode Range
: -7 Vdc to +12 Vdc max
●
Sensitivity
: ±200 mV
●
Bus Load
: 1/8 unit load (up to 64 meters)
●
Failsafe Modes
: bus open, shorted, and idle
