System-40 BTU Measurement System

Description

System-40 Series BTU Meters provide highly accurate thermal energy measurement in water and water/glycol heating and cooling systems. Each meter includes an integral inline flow sensor and a pair of precision matched temperature sensors. The compact design also features an easy to operate user interface and is available in several different configurations.

Aplication

Monitoring chilled water, hot water and condenser water in AHU and CRAC units for:
• Commercial office tenant billing
• Residential apartment and condominium
tenant billing
Monitoring renewable energy resources for:
• Solar thermal applications
• Ground source heat pumps
• Geothermal heating systems

Features

Reliable No-Moving-Parts Design - 
Wetted transducers measure the ultrasonic signal transit time differential, which correlates
directly to the flow rate. The direct beam path orientation significantly enhances signal
strength and long term reliability.
Highly Accurate Over a Wide Flow Range -
The flow sensor is accurate to within ±1% of reading over the normal (25:1 turndown)
operating range and within ±2% of reading over an extended (100:1 turndown) range.
User Friendly Backlit Display - 
The bright, easy-to-read, backlit display uses “smart button technology” to simplify page
navigation and programming. This eliminates the need for special configuration tools.
Matched Platinum 1000Ω RTD Temperature Sensors - 
Sensors are paired in a matching process that ensure a differential measurement
uncertainty of better than ±0.18°F.
Suitable for Water and Water/Glycol Solutions -
System-40 is field programmable for both water and water/glycol solutions to ensure accurate flow and energy measurement.
Detachable Display - 
The display for the system-40 is easily detached from the flow sensor. This allows for remote mount installation up to 5ft from the sensor body. 
Built-in Interval Data Logger - 
Energy and volume totals are date/time stamped and logged within the meter along with other analytical data. This data is available via BACnet®.
ACCURACY
±1% of reading over 25:1 turndown
±2% of reading over 100 :1 turndown
Overall turndown exceeds 500 :1
Repeatability: ≤±0.2%
Meets EN1434 Class 1 accuracy requirements
TEMPERATURE SENSORS 
Field serviceable MID certified matched pair of 2-wire 1000Ω platinum RTDs
Calibrated to a differential measurement uncertainty of ±0.18°F
Meets EN1434/C900.1 accuracy requirements for 3K sensors
CALCULATOR 
Computation error: ≤ 0.09% at 30°F Δt
Meets EN1434 Class 1 requirements with 3K minimum Δt
PIPE SIZE RANGE 
½ - 2½” nominal diameter
PIPING SYSTEM CONNECTIONS 
Male NPT threads 
2½” meter provided with ANSI Class 150 raised face flanges
FLUID TEMPERATURE RANGE 
32 to 250°F
MAXIMUM OPERATING PRESSURE 
400 psi
PRESSURE DROP 
Less than 1 psi at 4 ft/s, decreasing at lower velocities
MATERIALS 
Wetted components: Lead-free brass, PEEK
Enclosure: Polycarbonate
ENVIRONMENTAL 
Meets EN1434/C900.1 Class A requirements
Operating Temperature Range: -13 to 131°F
Storage Temperature Range: -14 to 158°F
Enclosre Rating: IP65
POWER SUPPLY REQUIREMENTS 
20-28V AC/DC, 50/60 Hz, 5 VA maximum
ISOLATED ANALOG OUTPUT 
May be programmable for energy rate, flow rate, supply temperature, return
temperature or Δt
Configurable as: 4-20mA, 0-5 V or 0-10 V output
ISOLATED TOTALIZING SOLID STATE CONTACT CLOSURE PULSE OUTPUTS
May be programmed for energy, volume, alarm indication, mode indication or MODBUS coil indication
Contact ratings: 50 mA, 30 V
Contact pulse duration: 50, 100, 500 or 1000 ms
ISOLATED TOTALIZING PULSE INPUTS 
For use with sinking open collector or dry contact outputs
Input rating: 30 VDC, 10 mA maximum
Pulse duration: 50 ms minimum
NETWORK CONNECTIONS Isolated RS485 serial interface
COMMUNICATION PROTOCOLS 
BACnet® MS/TP per ASHRAE Standard 135.1: 2009
MODBUS® RTU
NETWORK CONFIGURATION & ADDRESSING
Baud Rates: 4800, 9600, 19200, 38400, 76800, or 115200
Device Address Range: 1 – 255 (1 - 247 MODBUS® RTU)
Device Instance Range: 1 – 4,194,303 (BACnet® only)

Parity: None, Even, Odd (MODBUS® RTU only)

Reference : https://www.onicon.com/products/system-40-btu-meter/