7
Minimum Period Between Operations
Minimum setting period between levers L, marked ‘on’ and ‘off’ is fifteen minutes. When more than one pair
of levers are fitted, minimum period between consecutive “on’, ‘off’, levers is 1
3
/
4
hours.
For early operation switches, the hinged lever must be set at least three hours after normal lever L preceding
it and at least 1
3
/
4
hours before normal lever L following it.
On models Q559 and Q586 where two ordinary ‘on’ and ‘off’ levers are fitted, the early operation is effective
for one pair of ordinary levers only.
Setting the Solar Dial
Fixed ‘off’/change-over Operation Between 20.30 and 01.00
WARNING: Do not loosen the centre nut surrounding dial screw B
1.
Turn small five-point wheel D (Fig. 2) until correct calendar date is indicated through small aperture C.
Notes:
(a)
Each calendar month is divided into six equal divisions, each representing five days. The small pointer of date dial should
be made to indicate as nearly as possible correct day of month.
(b)
Switches are factory-set to operate automatically at sunset and sunrise in localities based on the Greenwich Meridian.
The operating pins are approximately in the centres of operating arms A and K (Fig. 2).
(c)
To compensate for longitudinal errors, variations of switch operating times (for a period of approximately
3
/
4
hour either side
of sunset or sunrise) can be achieved by suitable adjustment of operating pins within slots of operating arms. For convenience,
slots are calibrated in quarter-hour intervals.
(d)
Longitudinal correction, if applied, should be four minutes approximately for each degree longitude east or west of the
Greenwich Meridian. It is subtracted for longitudes east of the Meridian and added for longitudes west of the Meridian.
(e)
It should be unnecessary to adjust operating pins for latitudinal variations as dials are supplied for different latitudes.
2.
Turn main dial until the pointer P (Fig. 2) indicates time of day (Greenwich Mean Time) at the moment of
setting. The dial is calibrated in fifteen-minute divisions.
Models: S251 Form 13, S253 Form 13, Q551 Form 13, Q553 Form 13, Q550 Form 13.
1.
In the above models this operation can be obtained as an alternative to the one at sunrise. It is achieved
by transferring the operating pin from the solar operating arm A (Fig. 2) to the midnight bridge S.
2.
To transfer operating pin, procedure is as follows:
a)
Take out screw N (Fig. 2), and remove operating pin from arm.
b)
Fit operating pin to midnight bridge S, securing it with screw.
39659_Sangamo 18/1/05 11:52 am Page 7
