Chapter 4 – Using the F4T Front Panel
TestEquity 101H Temperature/Humidity Chamber
Page 25
Temperature Limit Alarm
The F4T has a built-in independent Limit Alarm. The Limit Alarm turns the chamber OFF if the
workspace temperature exceeds either a high temperature or low temperature limit. You can set
these limits to correspond to the maximum and minimum temperature that your test sample can
safely withstand. This provides protection against someone setting the temperature controller to a
condition that is unsafe for the test sample. It also provides protection in the unlikely event of a
chamber system component failure. The Limit Controller has its own temperature sensor
(thermocouple) and functions completely independent of the temperature controller functions.
!
CAUTION:
Always verify that the Limit Alarm’s high and low limits are set to
temperatures that are appropriate for your test sample.
!
CAUTION:
If your test sample is energized, it may can raise the workspace temperature
beyond safe limits. This could occur if your test sample exceeds the live load
rating of the chamber or if the chamber’s refrigeration system fails. You are
responsible for providing thermal protection devices to your test sample.
How to Set the High and Low Temperature Safety Limits
The Limit Alarm has separate Low Limit and High Limit Set Points. We recommend setting
these at least 5°C beyond the highest and lowest temperatures that the chamber is programmed to
reach to prevent nuisance tripping.
To enter the Limit Alarm settings, first press the
Menu
button (second button from the left below
the display). Then, press the
My Menu
button.
There will a 15-second delay before
My Menu
is populated if it is the first time you press it after
turning the Power switch on.
The screen which follows will provide access to the
Low Limit
Set Point
and
High Limit Set
Point
. Pressing the
Low Limit
or
High Limit Set Point
value will take you to a numeric key
screen where you can enter new values. Press
Done
after the values are entered.
