41
12.3.2
EXPANSION
VESSEL
SIZING
The following information is based on an inlet pressure of 3.5 bar and an expansion vessel efficiency of 0.45 using a standard 6 bar
unvented kit. If the system will have different parameters a more detailed calculation will need to be made.
V V = S V * e
0.45
Where:
V V
=
Vessel Volume
S V
=
System Volume
e
=
Coefficient of Expansion
Stored Temp.
C
30
35
40
45
50
55
60
e
0.005
0.006
0.008
0.010
0.012
0.015
0.017
Stored Temp.
C
65
70
75
80
82
85
90
e
0.020
0.023
0.026
0.030
0.031
0.033
0.037
12.3.3
COEFFICIENT
OF
EXPANSION
OF
WATER
AT
3.8
BAR
COLD
FILL
PRESSURE
12.4
CIRCULATING PUMPS
In order to ensure the correct flow rates through the water heater, the unit requires a bronze glanded pump sized to overcome the
resistance of the heat exchanger and a primary pipework loop. Lochinvar will supply a suitable bronze glanded shunt pump with
each water heater as shown in Section 12.4.1. The primary loop should be no longer than 14 metres plus the following fittings:
6 x 90
Elbows
2 x Unions
2 x Full bore lever ball valves
2 x Tee fittings (cold feed & building return)
For longer distances or a greater number of fittings, the pump may have to be resized.
The specification of this type of pump ensures that the bronze body and associated parts in contact with water are suitable for potable
use. A "glanded" construction is required to ensure that any scale in the system does not build up within the pump and cause a
resistance that can lead to a loss of water flow. Glandless (canned rotor) pumps are not recommended due to the fact that in hard
water areas, scale can build up within the rotor and failure can occur, not only of the pump but also the heater itself. The warranty
will be void if a failure of the heat exchanger occurs due to a "glandless" pump being used.
Model
Differential (K)
FLOW
(Litre/sec)
Total System Pressure
Loss (Meter- H
2
0)
Shunt Pump supplied
EKW46CE
10.0
0.98
7.32
LM900151A
EKW61CE
10.0
1.17
6.71
LM900151A
EKW86CE
10.0
1.80
6.07
LM900141A
12.4.1
FLOW
RATES
AND
SHUNT
PUMP
SIZES
Lochinvar will supply a suitably sized pump with all EcoKnight™ water heaters based on the parameters shown above, for projects
outside these parameters the pump will have to be re-sized.
Summary of Contents for ECOKNIGHT EKW116CE
Page 28: ...28 Max distance between brackets ...
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Page 55: ...55 15 8 WIRING DIAGRAM 15 8 1 WIRING DIAGRAM ...
Page 56: ...56 15 9 LADDER DIAGRAM 15 9 1 LADDER DIAGRAM ...
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