User Manual

2
Smart Infrastructure
CE2N5372en
2021-04-
06
Use
The heat (WSM5../WSM6..) and cooling energy meters (WSB5../WSB6..) and combined
heat/cooling energy meters (WSN5../WSN6..) are measuring devices to physically acquire
energy consumption. The device consists of a flow measuring section made of high-tech
plastic (WS.5..) or brass (WS.6..), 2 ready connected temperature sensors, and an electronic
unit which calculates the energy consumption from the flow and temperature differential. The
compact meter WS.. is of compact design and therefore ideally suited for use in apartments.
It is available in different versions for metering heat (WSM..) or cooling (WSB..) energy or
combined heat/cooling energy.
Restrictions:
The temperature sensors and battery of the WS.. compact meters cannot be replaced.
Functions
Meter design
The meter consists of electronic unit, flow measuring section and 2 temperature sensors.
The electronic unit is equipped with long-life batteries, ensuring up to 11 years of operation.
Ultrasonic measuring principle
The flow is acquired based on the non-wear ultrasonic measuring principle, which requires
no moving parts.
The amount of energy transferred from the medium to the consumer over a defined period of
time is proportional to the temperature difference between the warmer and colder side and
the volume of water that has passed through.
The water volume is measured in the measuring tube by ultrasonic pulses which are trans-
mitted in the direction of flow and against the direction of flow. Downstream, the time differ-
ence between the transmitter and receiver is reduced, upstream it is increased. The water
volume is calculated based on the difference in runtime.
The flow and return temperature is acquired by platinum resistors.
The water volume as well as the temperature difference between the warmer and cooler side
is multiplied using a heat coefficient and the product is integrated. The result, which is the
consumed amount of thermal energy, is stored and displayed in the physical unit kWh, the
volume in m
3
.
The WS.. uses an intelligent, adaptive temperature-measuring interval. With changing sys-
tem conditions (e.g. rapid increase of flow), the WS.. changes for a certain time to a fast
temperature-measuring interval. Thus, the meter always adapts itself to the current situation
and acquires the system temperatures very accurately.
NOTICE
In addition to heat energy, the meters measure cooling energy as an option that is added to
a separate tariff register (uncalibrated). Heat energy is always measured if the temperature
difference (> +0.2 K) and the flow is positive. Cooling energy is measured, if the tempera-
ture difference (< -0.2 K) is negative, while the flow is positive.
Processor unit
A common electronic unit applies to all flow variables.
Optical communication interface
The meter is equipped with an optical communication interface which facilitates readout and
configuration on site with the help of the optical read head WZR-OP-USP and matching
UltraAssist software.