Rotex E-Solar Unit ESU 509, Инструкция по установке и обслуживанию

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7 Electric heat generator
51
FA ROTEX ESU - 07/2008
7 Electric heat generator
7.1 Design and brief description
The electric heat generator of the E-SolarUnit is installed in a heat-insulated plastic housing behind the boiler control panel on the
cover of the heat storage tank. It consists of a stainless steel pipe surrounded by three tubular radiators. The welded tubular
radiators each heat the heating water with an output of 3 kW.
The tubular radiators are controlled by the heating controller. The ROTEX ALPHA
+
23R electronics monitor the flow and storage
tank temperatures against user settings and transfer a heat request signal to the relay board, if necessary. The relay board then
enables the tubular radiators in accordance with the operating mode, tariff type and corresponding output setting.
Each tubular radiator is protected from overheating by a safety temperature limiter (STL). The flow temperature sensor is
screwed into the flow connection cap, meaning it is positioned directly in the water flow. Thus, even if heat consumption is low,
any increase in temperature is detected quickly enough to switch the tubular radiators off before the safety temperature limiter
function is triggered. In case of a very rapid rise in temperature due to a malfunction, an additional STL cuts the heat generator
flow switching power of the power circuit board of the control panel.
7.2 Load compensation of switching contacts
The ROTEX ESU electronics consider the number of internal relay contacts and stores the operation time of each contact.
Requests made in partial-load operation are assigned to the switching contacts with shorter operating times.
7.3 Fault shutdown of tubular radiators
A fault shutdown occurs if the temperature at the tubular radiator exceeds 200 °C.
This situation can arise if

The heating circuit pump fails

The heating system is not sufficiently filled with water (water shortage)

The bypass (see Figure 2.1, page 8, pos. 27) is blocked or

The tubular radiator is faulty
1 Stainless steel pipe
2 Connection cover
3 Tie-rod
4 Electric tubular radiator 1 – 3 kW
5 Electric tubular radiator 2 – 3 kW
6 Electric tubular radiator 3 – 3 kW
7 Push-on connections for tubular radiators
8 Earth connection
9 Safety temperature limiter (STL) of the tubular
radiator
10 Return connection
11 Flow connection
12 Flow temperature sensor
13 Return flow temperature sensor
14 STL heat generator flow
Fig. 7-1 Top view on the ROTEX ESU with open heat generator cover and partially removed heat insulation
12
1
2
8
11
3
9 9 9 7
10
2
5
6
13
4
14
14
In partial-load operation, the output remains constant but the heating windings switched differ from one
switching operation to the next. This must be taken into account when performing tests on the unit.