Old Hussmann Rack Schematics

[Magoo83]

I recently started doing service at stores with really old hussmann racks! I am trying to understand the wiring inside the racks but I cant seem to find schematics anywhere for them! I think they have all decomposed inside the rack. I have searched online and cant find anything either.

One problem I had with ths rack is they have the alarm boxes inside that trip on ofc for each compressor, and then there are other causes of trips but I dont know what else makes them trip.

any help would be appreciated.

[Riverguy553]

Good luck with prints, since it's that old every Tom dick and Harry has hacked it up I would assume.

[Magoo83]

haha ya thats the other problem too. some of these racks are hacked up real bad, dont even know where to start

[bunny]

I see that that was a Hussmann Canada rack. They are no longer manufacturing in Canada....hard to tell if what they were producing was different from the US racks.

[jpsmith1cm]

Pics of the rack itself, please?


Hussmann has some information on their website under "Discontinued Equipment" and there are some diagrams floating around here.

You may be in for a challenge, though, as some of that stuff is orphaned and no information exists that I'm aware of.

[Phase Loss]

I'm thinking your alarm boxes are going to have a wire come from the alarm contact of each safety.

I think if you want a schematic on this racks circuits. your going to need: paper, pen, wire tie cutter and some time. And go old school.

[frigeguy]

I'm thinking your alarm boxes are going to have a wire come from the alarm contact of each safety.

I think if you want a schematic on this racks circuits. your going to need: paper, pen, wire tie cutter and some time. And go old school.

You would be correct Phase. I worked at Hussmann Brantford 1992-1998. (Install Mechanic) Bernie constructed the racks. There would be a few drawings around here but I don't remove them from the pannel. I pretty much know the wireing. Does it have a mechanical defrost clock ? Most of them here have been converted to cpc or micro thermal. Cool gas is warm !!!

[MikeySq]

HUssmann won't be much help i was once told that when they closed the plant in Brantford most of the files went MIA, coincidence? probably not. this era of rack all have similar wiring patterns, i think i may be able to dig up a drawing somewhere, i'll take a look.

for you alarm buttons you will have one for each compressor and extra ones for any satellite compressors and a liquid level float if equipped(A9 is usually liquid level)

Mike

[Magoo83]

heres alarm box. this rack had 6 comps, so 6 buttons for each comp right? then what would bottom 2 alarms be? al and at?

[jpsmith1cm]

http://hvac-talk.com/vbb/showthread....light=Hussmann

Maybe you can find some help with these diagrams.


These are from a much older system, but the alarm box is the same.

[bunny]

heres alarm box. this rack had 6 comps, so 6 buttons for each comp right? then what would bottom 2 alarms be? al and at?

That looks like the typical set of alarm buttons from an old Hussmann New System (no pun intented there).

I'd have to dig up some old manuals to see what they were for. One certainly was for low liquid alarm.

[icemeister]

I'd forgotten about that thread jpsmith1cm linked to.

I agree with bunny about the "AL" being a liquid level alarm.

The "AT" was most likely for the defrost timer. In those days Hussmann used a Precision gang timer with dual drive motors. If one motor failed, the other kept the clock working, but the timer's alarm contacts closed indicating the motor failure.

[frigeguy]

heres alarm box. this rack had 6 comps, so 6 buttons for each comp right? then what would bottom 2 alarms be? al and at?

Im pretty sure the bottom one was low receiver and the other was a low pressure. Its been a while. I stand corrected just read your post ice ...thats correct time clock has alarm contacts.

[frigeguy]

If I remember we have a main liquid line solinoid with a 20 lb loaded check on the right, beside control pannel for cool gas differential. This is the same on both med and low, they did alot of med temp cool gas defrost back then. The defrost slide valves are no fun to work on.

[-frozen-ocean-]

A1-comp #1
A2-comp#2
A3-comp#3
A4-comp#4
AD-defrost timer or controller
AL-low liq alarm
AS1-satellite comp #1
AS2-satellite comp# 2

[-frozen-ocean-]

older racks late 70's early 80's

A9- timer motor
A15- satellite
A16- satellite

Also there is high suction button on some racks.
AT- I think is low pressure
WTF- On most racks only between 2am and 6am

[Frostmonkey74]

I have 3 of these racks at one of my stores, not exact model number but same era, same control strategy I actually happen to have a schematic I drew up ( the old school way) I'll try n scan it this week and send it to you!!

And as indicated al is low liquid level alarm, and at is defrost timer alarm..

[Fridge Repairer]

Gosh that is an old rack. I havent worked on one of those in years. So far the guys are correct. I thingk too that the middle buttons were for each compressor alarm circuit as well.