14
3.5 Timer
Controls
The 100 hour timer works with Channel 1 only, it has no effect on Channel 2.
The timer circuit works in conjunction with the digital meter to determine when power is applied to the heater.
The digital meter is the actual temperature controller, the timer circuit only acts as a
gatekeeper
to determine if the
digital meter (temperature controller) is allowed to apply power to the heater or not. By inserting the timer
between the digital meter and the heater, the timer can turn heater power On or Off based on a user entered time.
When power to the controller is turned on, the timer defaults to the
Power Off
state as is indicated by the
word Off in the display. In this state no power is applied to the heater. This is a safety feature that insures
that power is not applied to a heater following recovery from a power failure.
The timer has 4 states
and cycles between
the states by pushing
the silver timer knob
momentarily.
For example, push the
timer knob once and
the timer changes
from the Off state to
the On state, push it
Push
Push
Push
Push
NOTE: Pushing in on the timer knob quickly for about 1/4 second causes it to advance to the next
state. Holding in the knob for 1 second changes to the mode where time is entered into the timer.
again and it changes to the toFF state. Repeatedly pushing the knob cause the time to cycle between its three
normal states of On, toFF, and t-on. If the Power Reduction Circuit (Section 3.6) is set to the Heat Off
position, the timer window always displays oFF.
The four states of the timer circuit are explained below.
In the off state, no power is applied to the heater, even if the temperature meter calls for
power to be applied.
The controller always enters the off state when power is turned on or following recovery
from a power failure. The controller also enters the off state when the power reduction
circuit is set to the Heat Off position (see Section 3.6).
In the on state, the timer circuit applies power to the heater when the temperature meter
calls for power to be applied. Whenever power is applied to the heater, the small LED
dot
on the left of the timer window is lit. Depending on the power needs of the heater, this dot
may blink rapidly.
The “toFF” state (standing for Time Off) allows the user to enter the amount of time the
controller should heat until heating is automatically turned off. While time is present in
the timer, power is applied to the heater, when the time counts down to 0, heating is turned
off. See the section below titled Heating for a Set Period of Time.
The “t-on” state (standing for Time On) allows the user to enter an amount of time to delay
before applying power to the heater. While time is present in the timer, no power is
applied to the heater even if the temperature meter calls for power to be applied, but when
time counts down to 0, heat is turned on indefinitely. See the section below titled Delay
Heating for a Set Period of Time.
