REMEHA P 420, Технические инструкции

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Remeha P 420 06/04/06 - 300008441-001-C
2 Important recommendations for connecting the boiler to the heating circuit
Installation must be carried out in accordance with the prevailing
regulations, the codes of practice and the recommendations in these
instructions.
` Minimum safety valve flowrate as a function of maximum boiler nominal output :
Minimum relieving capacity
Maximum gross boiler output
Example
Maximum boiler nominal output is 500 kW.
Minimum safety valve flowrate must be 4000 Kg/h
`
Water flow in the boiler :
The water flow in the boiler when the burner is operating must correspond with the following formulae:
- Nominal water flow Qn = 0.86 Pn/20
- Minimum flow Qmin = 0.86 Pn/45 (this flow also corresponds with the minimum recycle flow in the boiler)
- Maximum water flow Qmax = 0.86 Pn/5
Qn = flow in m
3
/h
Pn = Nominal output (full boiler output) in kW.
` Operation in cascade
After stopping the burner:
- Timeout required before the order to close a butterfly valve: 3 min
- Switch a possible shunt pump (located between the boiler and a butterfly valve) off via the end of run contact of the butterfly valve
` Operation with 2-stage burner
- The water temperature in the boiler is maintained at 50°C or more ; the first stage must be set to a minimum of 30% of the nominal stage
- Operation at modulated low temperature (minimum outlet temperature: 40°C) ; the first stage must be set to a minimum of 50% of the nominal
stage