MHS Boilers Ultramax 115, Operating & Maintenance Manual, Page: 24 / 46

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011204 24
Fig. 8 Condensate discharge
5.4 Hydraulic system
5.4.1 General
Although it is not the intention to provide a complete handbook covering the most divergent
hydraulic systems, the data is more extensive than would generally be provided in the case of
conventional central heating boilers.
The Ultramax unit is a low water content boiler for which the water flow rates must be within minimum
and maximum values.
Table 8 lists the required relationship between the three parameters Q (water flow), P (pressure)
and t (temperature) at maximum capacity. Because of the high flow rate, the appliance is less
sensitive to water hardness. Therefore, the water hardness may not exceed 250 ppm with a supply
temperature of 80
°
C (see 5.4.5 Water quality.)
5.4.2 Water flow
5.4.2.1 Flow rate and resistance
The rate of water flow through the appliance must never fall below the required minimum
(otherwise the water flow switch will be activated and the appliance will be shut down.) The use
of valves, non-return valves, systems in which several appliances are connected to a common
transport system, etc., must not interfere with the required water circulation.
∆ T 22 K Pump data
Nominal
flow
rate
Boiler
Resistance
Grundfos
pump
type
Pump
speed
Head at
Qnom.
Available
head at
Qnom.
Max.*
power
consumption
Type
m
3
/h kPa UPS kPa kPa W
73 2.72 17.0 25-80 3 66 49.0 245
90 3.51 23.5 25-80 3 58 34.5 245
115 4.52 30.0 32-80 3 52 22.0 245
146 5.48 30.0 32-80 3 45 15.0 245
192** 7.25 20.0 32-120F 3 75 55.0 380
241** 9.05 23.0 32-120F 3 65 42.0 380
287** 10.85 32.0 32-120F 3 52 20.0 380