Drazice TO 10 IN/UP, Руководство по эксплуатации и установке, Страница: 29 / 54

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mounting the safety valve onto a branch pipe. This allows easier exchange without having to drain
the water from the heater. Safety valves with fixed pressure settings from the manufacturer are
used for the assembly. Starting pressure of a safety valve must be identical to the maximum
allowed heater pressure, and at least 20% higher than the maximum pressure in the water main. If
the water main pressure exceeds such value, a reduction valve must be added to the system.
No stop valves can be put between the heater and the safety valve.
During the assembly, follow the guide provided by the safety equipment manufacturer. It is
necessary to check the safety valve each time before putting it into operation. It is checked by
manual moving of the membrane from the seat, turning the make-and-break device button always
in the direction of the arrow. After being turned, the button must click back into a notch. Proper
function of the make-and-break device results in water draining through the safety valve outlet
pipe. In common operation, such a check needs to be implemented at least once a month, and
after each heater shutdown for more than 5 days. Water may be dripping off the drain pipe of the
safety valve; the pipe must be open into the air, pointed down; environment temperatures must
not drop below zero. When draining the heater, use a recommended draining valve. First, close
water input into the heater.
Find necessary pressure values in the following table.
For proper safety valve
operation, a backflow
valve must be
mounted on the inlet
pipes, preventing
spontaneous heater draining and hot water penetrating back into the water main.
We recommend that the hot water distribution from the heater was as short as
possible to minimise heat losses.
Heaters must be provided with a discharge valve mounted on the cold service water inlet
to the heater for potential disassembly or repair.
8. ELECTRIC INSTALLATION
The electric wiring scheme is attached in the manual to the water heater (Fig. 2). The heater has to be
connected via a separate supply with a front-end main switch. The heater is connected to the 230V/50Hz
electric network using a conductor with a contact plug fitted with a switch that turns off all network poles
and the circuit breaker (protector). Electric installation must comply with valid electrotechnical standards.
Safety valve starting
pressure (MPa)
Admissible operating
water heater pressure
(MPa)
Max pressure in the
cold water pipe (MPa)
0.6 0.6 up to 0.48
0.7 0.7 up to 0.56
1 1 up to 0.8