Troubleshooting Safety Limit #2 on Koolaire Ice Machine July 13 2015, 4 Comments

Koolaire ice machines, that shut down prematurely may be turning off due to a safety limit. This article covers the Safety Limit #2 indicator and items to check to help diagnose your ice maker. This feature helps protect your investment, by shutting down the equipment, to prevent damage to parts like the compressor, control board, or evaporator.

What is Safety Limit #2

Troubleshooting Safety Limit #1 On Koolaire Ice Machine July 08 2015, 5 Comments

Koolaire, like other Manitowoc made ice machines, come with a built in safety limit feature on the control board.  This is a feature that shuts the ice machine down, if certain limits are reached, to protect the ice maker and its individual components. If the machine were not to shut down with these limits, you could potentially damage your compressor, evaporator, or electronic board. Although frustrating when the ice maker goes down, these safety limits protect your investment. This article will discuss the checklist and things you should check if your Koolaire were to shut down on Safety Limit 1.

What Does Safety Limit #1 Mean

Safety Limit #1 is activated whenever the ice machines freeze time exceeds 60 minutes for 3 consecutive cycles. If your ice machine has not made ice with 60 minutes, it's not going to. The typical freeze time should be 12-15 minutes max. Anything taking longer indicates there is a problem, or your ice machine needs to be cleaned. Either way, a shutdown is warranted after 3 cycles in a row.

Manitowoc S Series Ice Machine Safety Timers January 15 2015, 4 Comments

Manitowoc S Series ice machines are considered the best commercial ice machines produced.  They had just the right mix of new technology and old technology that made a reliable, long lasting piece of equipment.  The longevity of the S Series, like model SY0454A, SD0302A, SY0304A, and SY0604A, is due to the control boards ability to protect expensive components with safety timers.

Safety timers are used to shut off the ice machine, in case an ice making cycle is out of spec.  This provides protection to a compressor, that may be short cycling, or loss of water through inlet valves.  Below are the 3 main safety timers, which are indicated by flashing safety limit lights on the control board.

Safety Limit #2 On Manitowoc Ice Machine January 09 2014, 133 Comments

When your Manitowoc ice machine shuts down prematurely, it most likely is going off on what’s called a safety limit.  On Q Series ice machines there are 2 different safety limits, that will help you diagnose the problem.  To check the which safety limit is the problem, simply turn your machine from the off position to ice and count how many times the harvest light flashes.  Below are what the 2 safety limits mean.

Safety Limit #1 : If the freeze time reaches 60 minutes, the control board automatically initiates a harvest cycle.  If 3 consecutive 60-minute freeze cycles occur, the ice machine stops.

Safety Limit #2 : If the harvest time reaches 3.5 minutes, the control board automatically returns the ice machine to the freeze cycle.  If three consecutive 3.5 minute harvest cycles occur, the ice machine stops.

Safety Limit #2 is a more common safety limit and can be caused by the ice maker simply being dirty.  A dirty evaporator will hold ice and not allow it to fall until it is mostly melted away.  Because there is not enough ice to force the water curtain open and break the bin switch, the machine simply thinks it never harvested.

Assuming your ice machine is clean, there are 2 other areas that are most common for shutting a Manitowoc Ice machine down on a safety limit #2.  A missing magnet on the water curtain or your water curtain being broken will cause your bin switch to fail.  The magnetic bin switch on a Manitowoc ice machine relies on proximity to the magnet to know when to terminate the harvest cycle.  This switch will not read if it does not make proper contact with the magnet.  To remedy this issue simply replace the water curtain.

Another culprit, which can also lead to intermittent problems, is a failed bin switch.  The only way to properly test a magnetic bin switch is to OHM it out and look for consistency.  However, it is possible for the switch to fail on say the 100th time, so if you are experiencing regular Safety Limit #2 lockouts, it might be a good idea to go ahead and eliminate the bin switch by replacing it.