Operating Conditions; Frost Protection; Insulating Shells; Non-Return Valve - Grundfos MAGNA3 Montage- Und Betriebsanleitung

2.3 Operating conditions

1
2
3
4
Fig. 2
Operating conditions
2.3.1 Liquid temperature
See fig. 2, pos. 1.
Continuously: -10 °C to +110 °C.
Domestic hot-water systems:
• Up to +65 °C.
2.3.2 System pressure
See fig. 2, pos. 2.
The maximum permissible system pressure is stated on the pump
nameplate.
2.3.3 Test pressure
The pumps can withstand test pressures as indicated in
EN 60335-2-51. See below.
• PN 6: 7.2 bar
• PN 10: 12 bar
• PN 6/10: 12 bar
• PN 16: 19.2 bar.
During normal operation, the pump should not be used at higher
pressures than those stated on the nameplate.
Pumps tested with water containing anti-corrosive additives are
taped on the flanges to prevent residual test water from leaking
into the packaging. Remove the tape before installing the pump.
The pressure test has been made with water containing
anti-corrosive additives at a temperature of +20 °C.
2.3.4 Ambient temperature
See fig. 2, pos. 3.
0 °C to +40 °C.
The control box is air-cooled. Therefore, it is important that the
maximum permissible ambient temperature is not exceeded
during operation.
During transport: -40 °C to +70 °C.
2.3.5 Sound pressure level
See fig. 2, pos. 4.
The sound pressure level of the pump is lower than 43 dB(A).

2.4 Frost protection

If the pump is not used during periods of frost,
Caution
necessary steps must be taken to prevent frost
bursts.
Additives with a density and/or kinematic
Note
viscosity higher than those/that of water will
reduce the hydraulic performance.
12

2.5 Insulating shells

Insulating shells are available for single-head pumps only.
Limit the heat loss from the pump housing and
Note
pipework.
The heat loss from the pump and pipework can be reduced by
insulating the pump housing and the pipework. See figs 3 and 4.
• Insulating shells for pumps in heating systems are supplied
with the pump.
• Insulating shells for pumps in air-conditioning and cooling
systems (down to -10 °C) are available as accessories and
must be ordered separately. See section 17.3 Insulating kits
for air-conditioning and cooling systems.
The fitting of insulating shells will increase the pump dimensions.
Fig. 3 Fitting insulating shells to the pump
Fig. 4 Insulation of pump housing and pipework
Do not insulate the control box or cover the
Caution
control panel.

2.6 Non-return valve

If a non-return valve is fitted in the pipe system (fig. 5), it must be
ensured that the set minimum discharge pressure of the pump is
always higher than the closing pressure of the valve. This is
especially important in proportional-pressure control mode
(reduced head at low flow). The first non-return valve is included
in the pump setting as the minimum setpoint is 1.5 metres.
Fig. 5 Non-return valve