Discussions marquées : Repair and maintenance

UNICEF/WHO guidance on Decommissioning and safe disposal of CCE now available in ARABIC and RUSSIAN

Dear TechNet-21 community, Further to the publication of the English and French versions of the Decommissioning and safe disposal of cold chain equipment guidance earlier this year (available here https://bit.ly/2xTLDYa), we are glad to share with you that the Arabic and Russian versions of the document are now available in the TechNet-21 Resource Library. To access these documents, please click on the following links:
1. For the Arabic version:  https://www.technet-21.org/library/explore/cold-chain-equipment/5041-decommissioning-and-safe-disposal-of-cold-chain-equipment-arabic
2. For the Russian version: https://www.technet-21.org/library/explore/cold-chain-equipment/5042-decommissioning-and-safe-disposal-of-cold-chain-equipment-russian On behalf of UNICEF and WHO, I wish you an insightful reading and look forward to interesting and fruitful discussions with the TechNet-21 community! Michelle Seidel, Cold Chain Specialist - Immunization Supply Chain, UNICEF Programme Division (UN City Copenhagen)  

Powering Auxiliary Loads in SDD Systems – Energy Harvesting: Is It the Best Alternative?

One of the beneficial features of SDD refrigerators is its relative simplicity. Electrically two wires from the solar array are directly connected to the compressor. This simplicity minimizes problems in the field and simplifies repairs. Energy harvesting technology introduces a great deal of electronic complexity and the complexity increases as a larger percent of the available energy is harvested. In the US the primary mode of failure of new refrigerators is the electronic circuitry. In the field there will be different types of energy harvesting devices coupled to different brands of refrigerators and the loads connected to the device will be of varying types, ie batteries, resistive loads, pumps etc. these factors will complicate the determination of  a cause of failure and will also complicate training of the repair person. If the energy harvesting device does fail there may not be the power necessary to call a repair person. If a USB charging port is created it is desirable to provide power throughout daylight hours so devices such as smart phones and I pads can get fully charged. The simpler harvesting technologies only provide auxiliary power when the refrigerator is not running and the more complex technologies could provide a USB port throughout the day if there is sufficient excess power when the refrigerator is running.    A simpler strategy to supply energy for auxiliary loads may be to add a small stand alone power system. A 100 watt $100 solar module could typically provide 500 watt hrs of continuously available reliable power. A USB charging station can be powered by a panel between 6 and 20 watts, the cost of the system would be between $15 and $50, and these systems do not require a battery. Although the idea of energy harvesting is intriguing it may not be the most reliable and cost effective way to supply power for auxiliary loads.

Invitation for best practices sharing: Cold Chain Equipment Decommissioning and Disposal

Dear TechNet community members, Warm greetings! The cold chain situation in many countries is sub-optimal and affects the capacity of national immunization programs to deliver potent vaccines to all women and children.To help improve this situation, the Gavi Board approved the Cold Chain Equipment Platform Optimization Platform (CCEOP) in 2015 with the purpose to support the purchase of CCE. Since 2016, CCEOP WHO pre-reviews and GAVI Independent Review Committee (IRC) revealed countries’ weaknesses to provide updated and specific policies and strategies for CCE decommissioning and disposal. Though there is no policy for vaccines CCE decommissioning and disposal, countries should plan for technical support and request guidance.This could be major barriers to the implementation of the CCEOP or any future CCE investments. So I am contacting you, Dear TechNet community members, to request for best practices sharing from your countries.  Existing CCE decommissioning and disposal policy or strategy or plan for immunization Available CCE decommissioning and disposal guidelines for immunization Existing partnerships between National Immunization programs and other stakeholders (public-private-NGO) Your contribution will be very helpful to UNICEF which commits supporting countries developing policies and strategies for CCE disposal in the framework of the CCEOP implementation. Thanks for considering this request and I am looking forward to your reply. Dorothy.  

Looking for templates of Cold chain equipment repair & maintenance record, spare parts record.

Dear colleagues, I am looking for a template of cold chain equipment repair & maintenance record, a template of CCE spare parts record etc which can be used as specimen in training materials on CCE repair and maintenance in the immunization programme. Links, reference documents etc will be highly appreciated. Thank you for your cooperation.

Measurement of Condensation

We are working with ILRs. While daily operations, it was found that there is formation of water droplets inside the device. We want to measure the amount of condensation taking place inside the device in a day. We also tried to calculate the Dew Point Temperature but not much useful. Kindly suggest some method or way to measure the condensation. Regards Akhil

Two collections of WHO equipment maintenance resources (user and technician)

Thanks to the flexibility of the TechNet-21 website, I can share two older (circa 1985) collections of densely technical and highly practical equipment maintenance documents developed by WHO using the TechNet Resource Library (TRL). Once only available in hardcopy or in a digital corner of the online PATH Vaccine Resource Library, these materials are now available in two TRL collections:
WHO User's Handbooks for Refrigerators and Cold Stores
A series of booklets to help refrigerator and cold store users look after their equipment better. Developed in 1983, includes user handbooks on compression, kerosene and electric, and gas and electric refrigerators, as well as cold stores. Contents in all booklets include: actions on receipt, parts list, starting process, periodic attention needs, fault-finding, and maintenance and repair tasks.
WHO Technician's Handbook for Compression Refrigerators
Technician's Handbook for Compression Refrigerators materials were produced in 1985 by WHO EPI to improve the standards of refrigerator and cold room maintenance and repair. These were course materials to support a 10 working day course for repair technicians.
Please take a moment to look at these unique materials and other great finds in the TRL.

Best regards,

System design: Repair or Replace

A new policy paper on the vaccine supply chain, "System Design: Repair or Replace," has recently been released. It's attached and can also be found here: http://villagereach.org/vrsite/wp-content/uploads/2009/08/villagereach-system-design_repair-or-replace.pdf. This paper considers the broader concept of system design and how all components of a supply chain can fit together to be most efficient. This is the third paper in the VillageReach Final 20 series that looks at the different components of the supply chain, addresses the challenges faced at the last mile for distribution and presents examples of innovative approaches to address those challenges.

Standard Operating Procedure for Fridge Maintenance

Dear All,

I am a project coordinator for Nexleaf Analytics. We are a nonprofit organization dedicated to building low-cost technologies that create positive health, environmental and social impact. I have attached a Standard Operating Procedure (SOP) for fridge maintenance for your review. Additionally, I have also a little bit of the background about why we have created this SOP.

Nexleaf Analytics is currently deploying ColdTrace, our low-cost remote temperature monitoring device, in about 50 clinics in a district in Kenya and in about 100 sites in Mozambique. If a fridge experiences temperature excursions outside of the 2-8 degrees Celsius for a certain period of time, the ColdTrace sensor sends SMS alerts which notify clinic workers and Ministry of Health staff about vaccines reaching critical temperatures. Each level of the supply system can act on this information to help ensure vaccine safety. The goal of ColdTrace is to increase fridge up-time , improve the maintenance loop, and avoid vaccine wastage due to temperature excursions.

During my recent visits to Kenya and Mozambique, I learned the importance of creating a SOP for nurses that guides actions in three areas: (1) Preventive Fridge Maintenance; (2) What to do when they receive an SMS alert about a cold excursion: and (3) What to do when they receive an SMS alert about a hot excursion.

This SOP was also reviewed by the MOH maintenance departments in the two countries. This draft was slightly modified for Mozambique and translated in Portuguese. I would be more than happy to share that draft if anyone is interested.

I would greatly appreciate your feedback on this SOP as we are looking to make this SOP as comprehensive as possible. Thank you.

Leveraging fridge holdover time to allow for repair before temperature excursion

We think of fridge holdover time (autonomy) in the context of power shortage, whether cloudy weather in the case of solar, or power cuts for A/C systems.

While this will see functioning equipment through power shortages and keep vaccine 'safe' for a given duration (a parameter which varies immensely in function of the technology chosen) if there is an actual failure in the system, we're losing out on the opportunity to notify users of the failure so that technicians can arrive on site repair the system before temperatures go out of range.

At a larger facility, one could argue that stocks can be moved from a broken fridge to a functioning one, but many community level health facilities only have that one fridge and once it goes out range, vaccine life starts dropping much faster (function of specific antigen and ambient storage temperature).

At the moment, the majority of systems just have a power LED and perhaps an LED to show that a compressor is running. If systems had a circuit that diagnosed any failure, and in turn lit up a "Fault" light, users at sites could call for help, and technicians could arrive before the device's temperature goes out of the acceptable range. In an ideal world, fridges would also be equipped with SMS capability and technicians would be notified directly of failure with a countdown based on autonomy to indicate how long they have to get to the site before vaccines are "in peril".

In the meantime, I would be curious to hear from manufacturers, for technologies currently in the field, how a user could preemptively become aware of a failure for specific products. While such diagnostics in the absence of a global "Fault" reporting system may not cover every possible failure, perhaps such knowledge, if imparted into users, could save a lot of vaccines.

Remote Production of Distilled Battery Water

In solar powered vaccine storage systems high quality wet cell batteries have the potential of lasting longer than sealed batteries. However, they periodically need the addition of distilled water. Distilled water can be hard to obtain in remote areas.

Sun Frost has developed a method using waste heat from the condenser or compressor to distill small quantities of water needed to make up for water loss in batteries.

If there is sufficient interest and support we could develop the concept into a commercial product.

If interested please contact Sun Frost.

Compressor Replacement Without a Vacuum Pump

Compressor Replacement Without a Vacuum Pump

Replacement of a compressor requires the use of a vacuum pump. Solar
powered vaccine refrigerators are generally located away from the
utility grid. Most vacuum pumps are powered by AC grid power making
compressor replacement difficult. We have developed a method of
removing the air from a system without the use of a vacuum pump. The
method requires the installation of an access valve on the high and
low side of the system.

Evacuation Procedure

1 - With the new compressor installed, turn on the compressor and
depress the access valve on the high side of the system. Monitor the
pressure on the low side of the system. When the pressure is as low
as it will go, close the access valve on the high side of the system
and turn off the compressor. This process will take about 5 minutes.
2 - Charge the low side of the system to approximately 14 psi.
3 - Wait about 3 minutes for the pressures on the high and low side
to equalize.
4 - Now turn the compressor on and depress the access valve on the
high side. When the pressure on the low side is as low as it will go,
let the high side access valve close and turn off the compressor.
5 - Repeat steps 2, 3 and 4. Note, on successive evacuations, the low
side pressure will not go as low because of the absorption of
refrigerant in the compressor oil and it’s slow release.
6 - Charge the low side of the system to approximately 14 psi.
7 - Wait 3 minutes for the pressure to equalize. Turn on the
compressor and depress the access valve on the high side. This time,
when gas is no longer coming out the high side access valve, let the
valve close. The air is now purged from the system.
8 - Charge the system with the appropriate amount of refrigerant and
turn on the compressor.
9 - Make appropriate adjustments in system charge if necessary.

Target service life for vaccine refrigerators

What service life do you think vaccine refrigerators should be able to provide? For example, some products may suggest a 10 year life while others suggest longer, with typical repairs. PQS requires a 2 year warranty for a vaccine fridge.
Solar powered vaccine fridge systems require solar electric modules (minimum 20 year warranty is typical and 20 year is required by PQS). Most also have batteries (5 year warranty per PQS).
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