User`s manual

58
3. Cooling
3.1 DYNAMOMETER COOLING
Proper cooling of the dynamometer is essential to ensure a long operating life and accurate measuring
results. All Magtrol WB/PB Series Dynamometers* are water-cooled to guaranty the best possible
heat dissipation.
* Note: PB 2.7 Series Dynamometers are available with (K) or without a cooling circuit.
3.1.1 connectionS
Note: The cooling tubes must have an inside diameter in accordance with
the indications on the corresponding dynamometer data sheets (see
Section 1.2). They must be fitted to the dynamometer using a metal
ring. Also, check for correct water flow direction.
The cooling water input is marked “Cooling water inlet” on the dynamometer housing. The other
nipple is used for the water outlet. Check for correct connections.
3.1.2 W
Ater FloW And PreSSure
The required cooling water flow rate can be worked out by means of the following formula:
Braking Power [kW] · 860 [l·°C/kWh]
Flow rate [l/h] =
Outlet Water Temperature [°C] − Inlet Water Temperature [°C]
* 1 kWh = 860 kcal = 3600 kJ
The dynamometer cooling system has been designed for an open outflow and freely flowing water
without back-pressure. The maximum input pressure must not exceed 2 bar.
3.1.3 c
ooling WAter conSumPtion
≈ 30 l/kWh at Δt = 30 °C (Metric)
≈ 8 gal/kWh at Δt = 86 °F (US)
3.1.4 t
emPerAture SenSor
The dynamometer is fitted with a sensor measuring the outlet water temperature. This sensor generates
an alarm in case of overheating.