Fig. C
page 27
9.2 Determining Permissible Lengths - P.D.K.
In the graph the solid line diagonal represents the relationship between the concentric flue assembly (and any extensions) and the 70Ø exhaust (and any
extensions or additional bends).
If, for instance, a concentric length of 3.25 metres was required and the 70Ø exhaust needed to be 10 metres the graph shows that this combination would
NOT be permissible as the intersection point would be above the solid diagonal line.
K
Where both lengths have been determined they can be applied to the graph to check that the installation is permissible. For example, if it was known that 2
metres of concentric flue and 4 metres of 70Ø exhaust were required, the values could be applied to the graph as shown in
. As the point of
intersection of the dotted lines is below the solid diagonal line, the combination of lengths is shown to be acceptable.
In the example shown, assume that the concentric part of the flue needs to be 2 metres long. Find the position of '2' on the horizontal axis of the graph and
then project upwards to the solid diagonal line. This is represented by the vertical thick dotted line. Where this dotted line intersects with the solid diagonal
line on the graph, project across to the vertical axis. As can be seen this corresponds with 14 metres. Therefore, the total equivalent length of the 70Ø
exhaust can be up to 14 metres. Any elbow equivalencies must be accounted for i.e. 93° elbows are equal to 1 metre, each 45° elbow to 0.5 metres.
Summary of Contents for Main Heat 12
Page 8: ...Fig 3 Fig 4 Fig 5 Fig 6...
Page 38: ...Example 1 Example 2 Example 3...
Page 40: ...Fig E Fig F...
Page 51: ...Fig 31 Fig 32 Fig 33...
Page 55: ...Fig 35 Fig 36 page 39 12 2 Checking the Combustion 1 Follow the flow chart opposite...
Page 56: ......
Page 63: ...Fig 45 Fig 46...
Page 66: ......
Page 69: ...Fig 55 Fig 56 Fig 57 Fig 58...
Page 72: ...page 52...
Page 74: ...page 54...
Page 75: ...DRY FIRE...
Page 76: ...page 55 IGNITION LOCKOUT...
Page 77: ...page 56 OVERHEAT LOCKOUT...
Page 78: ...page 57 FAN LOCKOUT NOTE The fan is supplied with 325 Vdc...
Page 80: ...warranty This does not affect the customer s statutory rights page 62...
Page 82: ...page 63...
