100
7 HYDRAULIC SEPARATOR
Where there is a primary production circuit with its own pump and a
secondary utility circuit incorporating one or more distribution
pumps, there may be system operating conditions in which pumps
interact, creating anomalous variations in flow and head in the cir-
cuits.
The hydraulic separator creates an area with reduced load loss
which keeps the primary and secondary circuits connected to it
hydraulically separate.
The benefits of use of hydraulic separator may be summed up as fol-
lows:
– flow in one circuit does not create flow in another if load loss in the
segment common to both is negligible.
– flow through the respective circuits depends exclusively on pump
flow characteristics, preventing reciprocal influence due to their
coupling in series.
– the production circuit has constant flow and the distribution circuit
has variable flow, conditions characteristic of today’s climate con-
trol systems.
With going into the problems involved in temperature changes induced
by separators in heating systems when flow changes between primary
and secondary, we shall suggest a criterion for scaling the hydraulic
separator on the basis of the thermal power of the primary circuit, pro-
duced by the sum of the thermal powers of individual boilers.
The hydraulic separator recommend has a bleed valve for getting rid
of air and an emptying valve for getting rid of sediments of impurities,
and is based on a hypothetical temperature difference of 15°C
between delivery and return in the boiler circuit.
The dimensions of the hydraulic separator diameter and of the inco-
ming and outgoing pipes are shown in the table below in relation to
the thermal power of the cascade.
N.B: The specifications for selection of the hydraulic separator sup-
plied here are approximate only; optimum size depends on the speci-
fic features of the system.
8 DISPLAYING ERRORS
The controller signals faults which may occur in the controller itself or
in the system. During regular operation, “Er” will appear in the event
of an error. “Er”.
Error indication
1 Press the row selection buttons to select row 50.
2 Press the plus/minus buttons to select the faults list.
Press to switch among error signals.
Errors which may occur in the controller:
The RVA 43.222 controller can receive and store an error code
and address for every faulty device in the system connected in the
network.
Example
– The first number identifies the error code (26)
–
The second number identifies the segment address of the defective
device (.01) – for segments 10 – 14 it uses the letters A, b, C, d, E.
– The third number identifies the device address of the defective
device (.01).
Thermal power (kW) ø D (DN) ø d (DN)
< 25 50 25
< 40 65 40
< 60 80 50
<100 100 65
<150 125 80
50
Display Unit
0…255 –
Display Description of fault
Empty No fault
10 Outdoor temperature probe
20 Heater temperature probe
26 Cascade delivery temperature probe
46 Cascade return temperature probe
50 Hot water temperature probe
58 Hot water thermostat
61 Fault in room unit
62 Incorrect room unit
70 Supplementary hot water tank temperature probe
81 LBP short circuit
82 LPB address collision
different devices on the same address)
86 PPS short circuit
100 Two master clocks present
140 Device address not permitted
145
Device connected with PPS not permitted
146 System set-up not permitted
Display Error description
26.01.01 Error with address of faulty device
Bleed valve
Emptying valve
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