Bosch WORCESTER Greenstar CDi Classic Series Technical Information page 33

Natural gas supply
Listed below is a representative example. Figures
for other appliances can be found in the relevant
installation manuals.
Model
42CDi Classic
36CDi Compact
30Si Compact
28i Junior
The gas meter and supply pipes must be capable of
supplying this quantity of gas in addition to the demand
from any other appliance being served. It is important that
a gas supply pipe of at least 22mm diameter is used. Under
no circumstances should the size of the gas supply pipe be
less than that of the appliance inlet connection. The meter
outlet governor should be capable of ensuring a dynamic
pressure of 20mbar (8in wg) at the appliance. Particular
consideration should be given to the resistance to gas fl ow
created by elbows, bends etc. Pipework should be sized to
overcome this resistance.
Liquid Petroleum Gas (LPG) supply
Listed below is a representative example. Figures
for other appliances can be found in the relevant
installation manuals.
Model
42CDi Classic
36CDi Compact
30Si Compact
28i Junior
The gas tank or bottles must be capable of supplying
this quantity of gas at a nominal pressure of 37mbar
(14.8in wg) at the appliance.
Electricity supply
A 3amp fused three pin plug and unswitched shuttered
socket outlet (both complying with BS 1362) or preferably a
double pole isolator with a contact separation of 3mm in all
poles supplying the appliance should be used.
The appliance electrical circuits are also protected by an
internal 2amp fuse. The appliance must be earthed.
Mains cold water supply
Water Authority requirement
A direct mains cold water connection is permitted by
Water Authorities. However, it is recommended that
reference be made to local requirements. In the event
Gas rate
of diffi culty, please contact Worcester Technical
3
4.40m /hr
Support Department.
3
3.93m /hr
Cold water connection
3
3.24m /hr
Connection should be made as shown in the pipework
3
3.02m /hr
detail and the appliance installed generally in accordance
with the layout shown on page 31.
Wherever possible, the cold supply to the appliance should
be the fi rst connection off the mains supply, in order to
minimise hot water fl ow reduction when cold water services
are operated. The fi nal 600mm of piping to the appliance
should be of copper only.
Gas rate
3.30kg/hr
2.80kg/hr
Cold water pressure
2.33kg/hr
To achieve the stipulated fl ow rate, a working cold water
2.22kg/hr
mains pressure of 1.3bar is required.
However, for the Greenstar CDi Classic range to achieve the
stipulated fl ow rate, a working cold water mains pressure of
between 1.2 and 1.9bar is required (dependent on model).
The appliance will operate at a minimum working pressure
of only 0.2bar (3psi); however a reduced hot water fl ow
rate should be expected. Back-fl ow prevention devices,
including water meters, can prevent the expansion of hot
water into the cold water main. However, this can result in a
pressure build-up that may cause damage to the boiler and
household devices such as showers, washing machines, etc.
In these cases, we recommend that a mini-expansion vessel
(Part No. 7 716 192 105) be fi tted adjacent to the boiler in
the cold water main.
MAINS WATER EXPANSION VESSEL:
A - Mains water inlet pipe
B - Non-return valve
C - Mini expansion vessel, Part No. 7 716 192 105
D - Boiler
C
A
B
D
33