Installation
21
20045163
GB
4.11
Hydraulic connections
The pumps are equipped with a by-pass that connects the return
line and suction line. The pumps are installed on the burner with the
by-pass closed by screw 6)(Fig. 22).
It is therefore necessary to connect both hoses to the pump.
The pump seal will be dammaged immediately if it is run with
the return line closed and the by-pass screw inserted.
Remove the plugs from the suction and return connections of the
pump.
Insert the hose connections with the supplied seals into the con-
nections and screw them down.
Take care that the hoses are not stretched or twisted during instal-
lation.
Install the hoses where they cannot be stepped on or come into
contact with hot surfaces of the boiler.
Now connect the other end of the hoses to the suction and return
lines.
4.11.1
Oil hydraulic system layout
1
Pump suction
2
Solenoid valve
3
Pump
4
Pressure regulator
5
Return pipe
6
By-pas screw
7
Pump return
8
Solenoid valve
9
Solenoid valve
10
Piping
11
Filter
12
Piping
13
Pressure regulator
14
Servomotor
M
Pressure gauge
P
Oil pressure switch
V
Vacuum gauge
4.11.2
Oil pressure switch
The oil pressure switch 15)(Fig. 2, page 7) is factory set to 43.5 PSI
(3 bar).
If the oil pressure goes above this value in the return piping, the
pressure switch stops the burner.
Burner starts again automatically if the pressure goes down under
43.5 PSI (3 bar) after burner shut down.
If a loop circuit with Px pressure feeds the burner, the pressure
switch should be adjusted to Px + 43.5 PSI.
D1224
Fig. 21
D2444
Fig. 22
