Supplied By www.heating spares.co Tel. 0161 620 6677
8
are located in the lower left corner of the bearing frame (frontal view). We also mount an external protective terminal
(brass M6 screw).
The paint has to be removed from the surface around the screw inside the case and on its outer side before fitting
of the protective terminal. We connect a protective conductor ended with a cable lug under the head of the screw
inside the case. On the outer side we tighten a brass nut with a fan-shaped washer. The second nut is used for
connection of the external protective conductor.
Simple and also more complicated regulation elements such as programmable indoor temperature controllers
(daily or weekly programme) are available at the PROTHERM electrical boilers company and through its contract
partners. For proper operation of PROTHERM electric boilers it is necessary to install controllers with zero output
voltage. The required current carrying capacity of output contacts of the controller is 230 V / 0,1 A. Indoor temperature
controllers with zero potential output are connected to RT terminals.
6.2. Cascade control
If the output of the boiler does not cover the heat loss of the building, there is a possibility to connect another heat
source to boilers of the 21 and 24 series. To enable so-called cascade control connect K 1 and K 2
terminals of the
controlling boiler with the PR 1 and PR 2 terminals of the controlled boiler. If there is a need for cascade control,
ensured by the spatial thermostat, we connect its control terminals with the PR 1 and PR 2 terminals of the controlling
boiler.
7. Operations
After connection of the electric boiler to the heating system (according to local conditions) the system is filled with
soft water and the tightness of the entire system is checked simultaneously. Additional sealing is made if necessary.
After completing installation, the operating thermostat function is checked along with the thermal cut-off, pressure
switch and control elements on the panel.
Note
: Before the initial start-up of the boiler it is necessary to set the boiler operating thermostat to the minimum
level, due to undesirable air intake. After the switch-on of the main switch of the boiler (the green signal light is lit)
and after checking the active function of the general remote control turn the operating thermostat of the boiler until
the LED diode of the first output level is lit. Subsequently, turn the operating thermostat back to the minimum level.
This will activate the after-running function of the pump with a duration of 2 minutes. It is recommended to repeat
this two times.
If the orange signal light is on, then the boiler has probably overheated or there was a water pressure drop in the
boiler. In the first case a professional service engineer should check the emergency thermostat above the control
panel, see pic.
7
.
The emergency thermostat is irreversible, so the failure has to be deblocked by a deblocking
button (a). In the second case there was a water pressure drop in
the boiler. This can be only solved by filling the system with water,
until the water pressure rises above 1 bar. The orange signal light is
then switched off.
Before an any check into an inside part of the electric boiler relevant
to parts which are in a contact with a water or a wiring it
ś
necessary
to fill following conditions:
-
to switch off the boiler by means of the room thermostat or
the operating thermostat
-
to wait for c. 2 minutes
-
to disconnect the boiler from off the pernament input
connection of mains (a circuit breaker)
-
to close valves under the boiler (inlet, outlet)
-
to drain a water from the boiler (drain cock)
After a finish of the control or a possible revision check before the
repeated switching of the electric boiler to the mains, if the water
doesn´t issue out of the boiler.
Diagram 7
