Choosing the correct bimetal length for duct limit switches is actually quite easy but very important. Selecting the wrong probe length can cause your switch to malfunction when needed. Be sure to determine your Limit Switch Element Length before making a purchase. When mounting a duct limit switch, it’s best if the bi-metal element reaches the middle of the air duct. The air in the middle of the duct often differs in temperature from the air towards the edge due to changes in pressure and turbulence. When air turns or encounters resistance, the airflow speed and temperature are affected.
To simplify, the larger the air duct, the longer the element required. If the element length is too short, the duct limit switch may receive inaccurate temperature readings, causing it to trigger at too low a temperature or to delay. To purchase, click here.
Choosing the Correct Bimetal Length
You’ve made a great choice in deciding to purchase a Firestat to ensure the safety of your home or building! Now, as you consider your options, you notice there are three different probe lengths available. But what’s the difference? Our adjustable temperature range Firestat’s come in probe lengths of 5 inches, 7.5 inches, and 11 inches. Selecting the correct length for your duct will ensure that the Firestat functions properly when you need it to. To determine which length you require, you’ll need to know the approximate size of the duct it will be installed in. The end of the probe that sits inside the duct should be positioned as close to the dead center of the duct as possible. This positioning allows the Firestat to accurately read the air temperature without being influenced by the temperature at the sides of the duct.
Tips to Remember
- Be sure to measure the size of your duct before purchasing a Firestat.
- Choosing the correct probe length will ensure that your Firestat works properly when needed.
- The probe length needed will depend on the size of the duct it’s being installed in.
- Select the probe length that allows it to sit as close to the dead center of the duct as possible.
