Memo - Back-Up Refrigeration Control System for the Pavilion's Ice Plant • • � � •
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Memo
To: Steve Stadler, Public Works Director
From: Don Olson, Pavilion Manager
CC: Jay Strachota, Facilities Director
Date: October 22, 2008
Re: Back-Up Refrigeration Control System for the Pavilion's Ice Plant
Staff would like to request funding for the installation of a manual back-up control system for the Pavi�ion's ice
making equipment.
Background: The Pavilion's current digitally controlled refrigeration system is original equipment, installed
eighteen years ago. The system included one of the first automated control systems in the industry at the
municipal ice arena level. The system is run by two computer control boards and is monitored by a computer
terminal. It is totally automated with only manual shut off safeties to prevent damage to compressors and other
motors in the system. The system does not have the ability to run if the computer control boards go down. The
• system was supported very well the first half of its life by the manufacturer of the system and also the distributer of
the control board components as they were very interested in the new market for these systems.
The original refrigeration manufacturer, Holmsten Ice Rinks, Inc. is not longer in business. The distributor of the
automated controls, Control Systems, Inc., is still around but the control board manufacturer, Andover Controls,
no longer manufactures replacement control boards for the Pavilion's system. The automated system concept
has been accepted by the ice arena industry, but is generally used only in larger municipal complexes, using
common HVAC automated controls, and with a manual run mode to override computer controls if needed.
A little over a year ago staff learned that it would be impossible to get a new automated control board from
Andover Controls if the board went down and needed replacement. What would be available are refurbished
boards and we were told refurbished boards might be scarce. Refurbished boards seemed to be a risky plan for
such a critical component of an ice arena, so staff began to explore the options. The options ranged in expense
from $10,000 -$70,000. Being the wide range in costs we knew we had to commit to an option before budgeting
or requesting funds. After speaking with vendors and other arena managers these are the options staff explored:
1. Replace the control system with a new updated system
2. Purchase refurbished computer boards and other components necessary to have on the shelf in the
event of a system failure
3. Install a manual system as a backup to the computer control system
The Problem: If the Pavilion's ice refrigeration system fails due to the computer boards going down, we could
have as little as 24 hours to repair the system before the ice sheet deteriorates to the point that it would need to
• be removed, and a new ice sheet installed. In a best case scenario, if the ice sheet is lost, it would take 5 days to
remove the old sheet and reinstall a new sheet. So if the system was down for two days while parts were located,
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next day.aired, and installed, we would be down a minimum of a week. The impact of that is one weeks revenue
$10,000, repair & overtime costs $6,000, and no way to make up lost ice to our customers as the season is
already fuily booked at the Pavilion, and other arenas. We also feel the trust factor would be violated with our
. customers if we lost the sheet. There would be a lot of questions knowing what we knew of the situation and
chose to delay action, if the ice plant went down, and we lost the sheet of ice, and we had not taken action.
Why do we think the control boards may go down? Hopkins experiences a lot of spikes, loss of phase, and
other power problems which is hard on electronic equipment. We have replaced two boards in 18 years, neither
one recently.
Option 1: Replace the control system with a new updated system
Cost: $65,000-$75,000
Recommendation: Staff does not recommend replacement at this time for several reasons. A new system can
be just as vulnerable to failure as the current system, and we would still be without a back up method of operation
under this option. We are less likely to lose an ice sheet under this option, but the race would still be on to rescue
the sheet especially on weekends and holidays when service and delivery companies are not working. There is a
possibiJity that the City may, in the future, go to a City building wide HVAC control system. At that time it would
make sense to incorporate the Pavilion's refrigeration plant into that system, rather than install a system at the
Pavilion now, that will be different than a future City system.
Option 2: Purchase refurbished computer boards and other components necessary to have on the shelf
in the event of a system failure
Cost: $5, 000-$8, 000
Recommendation: Even with the parts on the shelf, the boards are refurbished and we wouldn't really know
• what we have until they're installed, programmed, and ran. The possibility of losing an ice sheet still exists under
this option and it would still be a race to save the ice sheet. Repair potentially take a long time, jeopardizing the
sheet, as the number of qualified experienced service personnel to program these boards is limited due to the
age of the technology. Again, reaching these qualified technicians on weekends and holidays is not a sure bet
with this older technology. We could also spend $8,000 on parts that we will never use if the boards stay up and
running and we someday go to a web based City building wide HVAC control system. Staff feels this money
would be better spent on Option 3.
Option 3: Install a manual system as a backup to the computer control system
Cost: $30,000-$35,000
Recommendation: After considering the cost of the replacement option, and the risk associated with depending
on refurbished parts on the shelf, and maintaining old technology, staff feels the best option for now, and the
future, is to install a back-up manual system that allows us to continue normal refrigeration operation if the current
or future control system fails. A manual system would be independent of any automated controls, current or
future. This would allow us to continue operation of critical equipment under any control system scenario. This
would also save repair costs, and labor �costs in the future as we could operate under this back up system if a
board went down, and have time to consider our repair options, not pay overtime and weekend/holiday service
call fees, etc.
In conclusion, it is critical that action is taken during the non-ice season of 2009 to correct the problem with the
Pavilion's refrigeration plant to avoid potential loss of service. Funding is not identified currently for this project in
the CIP or Pavilion budget. Staff recommends the use of contingency funds or a City loan to the Pavilion to
accomplish this project.
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