Switch Sequence Diagram; Boiler Control; Introduction; Modulating Controls General (Two Wire Control) - REMEHA 610 ECO Technical Information

8.5 Switch sequence diagram

fig. 18 Switch sequence diagram
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8.6 Boiler control

8.6.1 Introduction

The Remeha Gas 610 ECO can be controlled using one
of the following methods:
Note: when using 2-stage control (each boiler module
on/off) the boiler modules will also modulate to main-
tain the flow temp set point (parameter !)
- Fully modulating, where the output modulates
between the minimum and maximum value on the
basis of the flow temperature defined by the modulat-
ing controller.
- Analog control (0-10 volts), where the heat output or tem-
perature is controlled per module by a 0-10 volt signal.
- 2-stage control (two volt free relays), where the heat
output of each boiler module modulates between the
minimum and maximum value on the basis of the flow
temperature set in the boiler module.
- 4-stage control (four volt free relays), where each
boiler module is controlled by means of a 4-stage
controller at part load and full load.
In all cases, modulation is based on the required flow tem-
perature and there is a dT dependent output control with
the following characteristic. Up to a dT of 25° (factory
setting, parameter H) the boiler module operates at full
output. Between dT and dT
full load
linear fashion (see fig. 19).
the output reduces in
part load
Remeha Gas 610 ECO
fig. 19 Output control characteristic
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8.6.2 Modulating controls general (two wire control)

To make full use of the boiler's modulating feature, a
rematic control can be connected. This control will
®
provide optimised time and weather compensation to
achieve maximum efficiency and minimum boiler cycling
whilst maintaining design condition within the building.
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