Diagrams: DR-
SG130, DR-SG131
page 2 / 3
B. OPTIONAL ACCESSORIES REQUIRED
No accessories needed.
C. OPERATING DESCRIPTION
The Dorchester DR-SG is coupled to 1 or 2 DHW tanks, the customer regulates the DHW setpoint
he wishes to obtain at the product outlet, which will be the same setpoint for the tank(s).
A pump is added between the tank and the Dorchester DR-SG that allows the entire volume to
be permanently stirred. This pump can either be directly connected to the customer's electrical
cabinet and operate permanently, or can be connected to the Dorchester DR-SG control panel.
/!\ Ensure you are in DHW comfort mode (2 cursor on the HMI) so that the DHW tank load pump
operates permanently. If you are in reduced mode (1 cursor on the HMI) the pump will not operate
as effectively as expected and the temperature of the water supplied to the network will not reach
the setpoint.
Check that the loop flow rate and temperatures comply with the regulations; if necessary, adjust
the loop circulator adjustment valve and/or the mixing tap setpoint.
the circulator between the tank and the Dorchester DR-SG is dimensioned to ensure a flow rate
equal to P / (1.16 x ∆T)
- with P being the nominal power of the Dorchester DR-SG (in kW) and
- ∆T = setpoint T – cold water T considering the temperature of cold water in summer.
However, it is imperative that this flow rate is higher than the loop return flow rate in the tank, once
you are sure of compliance with distribution loop regulations.
It should be remembered that the power of the Dorchester DR-SG must be determined on the
basis of DHW consumption but also taking into account the heat losses of the distribution loop.
Navistem Modbus
(option see § Navipass)
Fault report 230Vac
No modification to
be made
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00U07337760-A
DORCHESTER DR-SG -
Installation, Operation and Maintenance