PO ENGINEERING INSTRUCTIONS
MISCELLANEOUS
TIME
B 1361
Issue 4, Oct 1970
ELECTRICAL CLOCKS - SYNCHRONOUS TYPE
Clock No 56B
 One of the standard synchronous clocks at present used by the PO. The movements are described in B 1351.
Synchronous clocks are suitable for use only in areas where the mains supply is reliable. The basis for provision is given in B3001. The types used in the
PO are all non self-starting for use on a supply of 200-250 volts ac, single phase, 50 Hz, with a frequency which is time controlled. They should not be installed where
time keeping is of vital importance.
Clock No. 56B
Similar to Clocks No. 52B, but with circular cases. When used in a public office window, a clock of this type should be mounted by means of a Bezel, Clock No. 1 (Drawing P/T 102), which is described in B 1128. Superseded for new work by
Clocks No. 76B.
Picture shows clock mounted in Bezel, Clock No. 1.
Drawing No. P/T 93.
| No. |
Overall diameter |
Diameter of dial |
Depth (back to front) |
| 56B |
14.75in. |
12in. |
3.6in. |
|