The unit is suitable for controlling any appliance or device which is normally connected via a 13 amp 3-pin plug top. It is not recommended that the unit is used to control an open bar-type radiant electric fire. Unmonitored operation of this type of appliance could be hazardous. Nor should a plug-in timeswitch be used to control an immersion heater. This type of device should only be connected via a purpose-made hard wired immersion heater timeswitch.

Lighting loads put severe stress on switch contacts. A plug-in timeswitch can be used to control a table or ‘standard’ lamp, since this is a very modest load, typically 60 watts, taking

¼ amp, although even this will draw up to 5 amps when the lamp is first switched on. But a lamp fitted with a 150 watt bulb will take ¾ amp, and approximately 15 amps when first switched on - this could be switched O.K., but is already at the upper limit of the timeswitch’s capability. Fluorescent and ‘discharge’ type lamps should be avoided, since these impose an even heavier overload when first switched on.

The STA200 has a 24 hour dial with 96 tappets. Each tappet operates the output for 15 minutes.

A three-position manual override is built in to the dial of the timer. This provides for fixed on, timed, or fixed off control. Fix on or off is a permanent selection, which can only be changed by moving the manual override back to the timed position.

The STA450 is a seven-day version of the above unit. The STA450 works in a similar manner, but the dial is divided into seven sectors corresponding to the days of the week. Each day sector of the dial has 12 tappets so that each tappet operates the output for two hours. Different switching times on different weekdays can be accommodated. Hence the unit can ‘omit’ a day if required. The STA450 includes clock hands so that it is easier to set the current time correctly - without clock hands it would be difficult to align the dial accurately. A manual override is built into the dial. This operates in exactly the same way as the STA200 override.

The STA500 is an electronic 24 hour and/or seven day plug-in timeswitch. This unit can control the same types of devices as the other plug-in timers. The main difference with the electronic unit is the flexibility of programming. Programmed times can be to the precise minute. The unit has 20 programme spaces. Any programme space can be set for an individual day, or one of the day groups provided - when you press the ‘Prog.’ button, the unit automatically selects all seven days. You can also select Monday to Saturday, Monday to Friday, or Saturday and Sunday. If each programme space were used for all seven days, the unit would switch 140 times in total during the week.The STA500 also incorporates a special ‘random’ feature for security SPECIFICATIONS. The random feature operates as follows: if you have a sequence of on/off switching already set in the unit’s memory, you can press the ‘rnd’ button to make the unit switch approximately at the programmed times. It will never repeat the precise time of switching each day, because a ‘random generator’ inside the micro-chip of the timer makes the on/off times randomly different. The reason this is provided is specifically for security lighting control when a property is empty. There is a built-in ni-cad battery which provides minimum 150 hour backup to preserve the memory if the mains fails.

On the display of the STA500, the days are shown by numbers 1 to 7 across the top of the display; the time is shown in the twenty-four hour mode, although you can convert the display to twelve-hour a.m./p.m. display, by pressing the ‘h’ and +1h buttons at the same time. The display also shows the switch condition O = ON, O = OFF. O = manually advanced to ON, O = manually advanced to OFF (manual advance automatically resets with the next timed instruction). [O] = Fixed ON, [O] = Fixed OFF ( Fixed ON or OFF will only change by use of the button to put the output back to timed.