Analyzing Why A Safety Limit Stopped The Ice; Machine; Safety Limit #1 - Manitowoc indigo series Technician's Handbook

ANALYZING WHY A SAFETY LIMIT STOPPED THE ICE

MACHINE

Safety limits are designed to stop the ice machine prior to
major component failures, most often a minor problem
or something external to the ice machine. This may be
difficult to diagnose, as many external problems occur
intermittently.
Example: An ice machine stops intermittently on safety
limit #1 (long freeze times). The problem could be a low
ambient temperature at night, a water pressure drop, the
water is turned off one night a week, etc.
Refrigeration and electrical component failures will cause
a safety limit trip. Eliminate all electrical components and
external causes first. If it appears that the refrigeration
system is causing the problem, use Manitowoc's
Freeze Cycle Refrigeration System Operational Analysis
Table, along with detailed charts, checklists, and other
references to determine the cause.
The following checklists are designed to assist the service
technician in analysis. However, because there are many
possible external problems, do not limit your diagnosis to
only the items listed.

SAFETY LIMIT #1

Firmware version 5.010 and higher
Freeze time exceeds 35 minutes for 6 consecutive freeze
cycles.
Firmware version 5.09 and lower
Freeze time exceeds 60 minutes for 6 consecutive freeze
cycles.
Possible cause checklist
Improper Installation
• Refer to "Installation/Visual Inspection Checklist" on
page 136
116 Part Number STH025 11/16