coffin frezzer

[northern boy]

working on coffin frezzers there are three coffin frezzer on the same circuit of off a rack one of the frezzers always leaves the product with alot of frost build up on it after defrost cylce is over all drain times seem to be fine drain is not pluged but the fan's stay on during defrost hussmann employee say's that that is the way that the system is desinged i guess the question i'm asking is are the fan's actually supose to stay on during defrost or is this guy just jerking me around. or is there something that i am missing?

[innovator]

Is this gas defrost or electric, and how long is the defrost.
I might be incorrect, but I believe coffins need the fans on during electric or gas for Hussmann cases. What is the temperature of the case before it comes out of defrost?
If the defrost time is correct, it is likely your discharge air temp is too low. Is it below -20? F/F coffin should be -15 or so to eliminate frost....

[thegoodhumorman]

are those french Clouseau? :D


fans always run on electric tubs
on hot gas may terminate after a short period
or drop out immediately- would have a term stat for fans
(aka a fan delay!). some cases have seen run fans whole time...okaaay... not for me

run tubs too cold= frost
defrost too long=ice water on product
bad air band= frost on a particular case section-
anything disturbing air band?
AC register nearby, front doors, prevailing winds near front door (which I have seen before-wind tunnel effect).

Mod and maker would go a long way.
(whatever the hell that saying means anyway? )

[dirtyboy103us]

hussman cool gas defrost
yes fans on during and what yours piping run like and defrost termination temp and the air across the top of the case if the air curtain that keeps the humidity out is broken it will frost all product .... that is by any means.. ac vent or product being loaded to high... its snowing in your case for some reason ... high humidity and cold air = snow or frost.. if termination not working with a 30 to 45 min fail safe that would kill most product at about 80 degrees