Control.com - Nerds in Control

The 88bt1 and 88bt2 will both start when the 26bt2 change to 1, but this situation "Operating both vent fans while running." is unacceptable according to the TIL 1566 "HAZARDOUS GAS DETECTION SYSTEM RECOMMENDATIONS". so shall i change the CSP to meet the requirement of this TIL?

Who is the packager of the unit? If it's GE EPE (Energy Products Europe), include that qualification.

I'm going to say (without being able to look at the Heating & Ventilation piping schematic diagram and without understanding the sizing of the vent fans) that the sequencing is not really "standard." It appears that the sequencing is trying to prevent high compartment temperatures by starting the lag, or standby, fan when the temperature reaches the actuation set point of 26BT-2 (and you haven't told us what that temperature is).

The way some compartment vent fan sequencing works is to keep the lead vent fan running after the unit is shutdown until the temperature drops below the de-actuation set point of a temperature switch (sometimes that was 26BT-1, sometimes it was 26BT-2).

You should discuss this with GE; I'm not familiar with the details of TIL 1566 with regard to compartment vent fan sequencing and every unit is supposed to have an airflow study performed to analyze the particular characteristics in order to prevent possible pockets of hazardous gas from going undetected or un-ventilated; has this unit had such a study, or is someone trying to implement what they believe the intent of TIL 1566 to be?

Best to work this one out with GE. Provide as much information as you can when putting together the request; the above is not enough. They will ask for as-running or as-built schematic diagrams, Control Specifications, CSP, etc., so by including all that in the request you will save yourself lots of time and aggravation (okay, well, some aggravation at least; trying to get help with these kinds of problems can be extremely aggravating).

I will test the temp before and after the both vans start.