7.4 Combined heat/cooling metering
MULTICAL
®
402 is available as heat meter (Meter type 2xx), cooling meter (Meter type 5xx) or combined
heat/cooling meter (Meter type 6xx).
Meter type
If MULTICAL
®
402 has been supplied as a combined heat/cooling meter (meter type 6xx), it measures heat energy
(E1) at a positive temperature difference (T1 > T2), whereas it measures cooling energy (E3) at a negative
temperature difference (T2 > T1). Temperature sensor T1 (with a red type sign) must be installed in the hydraulic
forward pipe, whereas T2 (with a blue type sign) is installed in the return pipe.
If the current T1 exceeds, or equals θ
hc
only heat energy can be measured. If the current T1 is lower than or equals
θ
hc
θ
only cooling energy can be measured.
hc
is the temperature point used to change between heat and cooling measurement. θ
hc
In combined heat/cooling meters θ
is configurable in
temperature range 0.01…160.00°C.
hc
should correspond to the highest occurring forward temperature in
connection with cooling, e.g. 25°C. If the meter is to be used for ”purchase and sale of heat”, θ
hc
is set at
180.00°C, which cancels the θ
hc
If you want to switch the qhc function on or off compared to current condition, it is necessary to perform a total
programming of the meter by means of METERTOOL.
function.
The change between heat and cooling measurement involves no hysteresis (∆θ
hc
θ
= 0.00K).
hc
is configured by means of METERTOOL (see paragraph 14.2).