Open Trade Training Centre

Open Trade Training Centre (OTTC), is the leading training provider of commercial and industrial refrigeration courses & refrigeration training. 

Including Air-Conditioning and Ammonia.

We invite you to join the best refrigeration training in South Africa

Upcoming programs

Enroll now!

  • Safety Regulation, safety protection on plant, safety valves, safety switches, the dry evaporation system, expansions valve control, oil change and service procedures, cooling tower, evaporative condenser, shell and tube condenser, fault finding
  • Flooded system, ice bank = with HP float valve, LP level control, level switch control, flooded evaporator with hot-gas defrost, liquid pumps, oil filter
  • Plant instruction, operating of plant with liquid pump, two air-forced evaporators, hot-gas defrost, evaporator plate heat-exchanger with chiller-water cycle, trouble shouting, diagnoses and identification, oil drainage, air-purging V-belt alignment, charging of plant.
  • Servicing of various compressors, remove pistons, remove cylinders, remove shaft seal, check wear and tear, oil filter, suction filter, oil pump, servicing of shut of valves, repair and overhaul different valves.
  • Screw compressor for ammonia plant with liquid ammonia pumps, valve station with hot gas defrosts, surge drum for liquid pumps, problem solving, plotting of ammonia plant in the diagram, determining of cooling capacity.
  • Maintain safety in the handling of ammonia refrigerant
  • For persons working in Ammonia Sites, Fire brigades, First Aid Personal
  • Unit standard: 116- : 220-223-334-355-468-700-704 and as per SANS 10147
  • Knowledge of legislation concerning health, safety, and environmental standards i.e., OHSA, PER, Montreal
  • Standards knowledge of this standard SANS 10147.
  • Requirement’s assessments, calculate refrigeration capacity, select equipment and components, make flow diagram, Compile material list, Price material list, establish all other expenses, arrive at final selling price, commencing with small thermosyphon plant, followed by simple pump re-circulation plant, thereafter more complex plants, Course can be extended to last longer or be continued at later date.


refrigeration course

OTTC has a special project going for a set of 5 groups to do their Ammonia diploma’s and further their education and shape their skills so they can be safe and confident in the field in and around Ammonia plants.


ottc accreditation
OTTC refrigeration certificate
refrigeration training
refrigeration training courses

Diploma's being handed to proud students

Why study at OTTC?

Because we are the best in the industry.

OTTC has the vision to see what you as the student would benefit from most, in our famous Ammonia diploma, presented by non other then Mr. Kurt Johannsen(have designed over 500 plants).

New to refrigeration?

NO problem, our beginners program will get you started with the basic tool skills and knowledge about how to use them and will introduce you to your next step, being the Maintenance program.

Where you will learn the most effective and efficient way to assist your artisan in and around the plants.

Enroll now!!

Isolde Dobelin(Owner/Director) Social Profiles

The theoretical and practical of OTTC refrigeration training courses

The OTTC refrigeration courses are specialized for theoretical as well as practical training.

Refrigeration courses and the Ammonia course at OTTC are given with the highest quality learning material and the best lecturers.

Also have the best tailored air-conditioning training for air-conditioning services, duct cleaning and installation.

OTTC Refrigeration Training Descriptions

refrigeration training south africa

The program is designed for the first year apprenticeship. The outcome is a perfect assistant working efficiently with the Technician and is an asset to be employed.

refrigeration courses near me

The program is designed for the first year apprenticeship. The outcome is a perfect assistant working efficiently with the Technician and is an asset to be employed.

New installations on cold rooms and refrigeration plants, Servicing maintenance, repair, faultfinding, improvements for energy savings.

For the supervisors, plant operators and plant designers. Including commercial and industrial refrigeration, secondary cooling and CO2 plants.

refrigeration courses near me

For technicians, supervisors and designers working in the Air-Conditioning industry for heating and cooling on central Air-Conditioning plants.

air conditioning training

For people working in ammonia. Technicians, supervisors, operators and designers. Ammonia industrial plants are used for cold stores, dairies, breweries.

Please follow our info menu to course pages.

The OTTC Initiative

Everybody is welcome to do our courses.

We don’t ask for papers if you feel comfortable and eager to work hard and follow our programs you definitely will pass our courses and get a OTTC Diploma.

We might just ask if you have some working experience to see where we can start with you and give you the right advice and save you some money.

All courses include practical on our life-size training plants for better understanding.

Courses can also be done individually, one course at the time according to our program.

The OTTC Ammonia Diploma is a OTTC Ammonia Qualification established 1993 specially for the people working on ammonia plants, consulting engineers and contracting companies.

The OTTC AM-SH Ammonia Safe Handling Course is part of our AM-Diploma since 1993 and registered from OTTC with SAQA since 2004, this is an OTTC qualification developed by Kurt Johannsen BSc. Mechanical Engineer – 1969, Denmark, SAQCC Gas – Cat. C.  Reg. No. 1130 For South Africa and all OTTC Ammonia Diploma Students.

Never the less if a young inexperienced person, with good school grades and he/she wants to work hard, they are welcome to do our OTTC Ammonia Diploma.

The industry likes to give them a chance to employ them and gives them the practical experience to get started in a workplace.

About OTTC

OTTC – Open Trade Training Centre was founded by Peter, Susanne and Isolde Dobelin in 1992.

Peter Dobelin, German Master in Refrigeration, Air-conditioning, Heating and specialized expert in Ammonia.

He worked 11 years for Ahlborn Hildesheim (now GEA) and BBC York Mannheim as manager of work installing and maintaining Dairies, Breweries, Chicken and Chocolate Factories and many more places.

From his experience he felt there is an urgent need to establish the OTTC Ammonia Diploma Qualification to safeguard and protect especially people, also the high investments on ammonia plants.

This OTTC Ammonia Diploma Qualification was immediately accepted by the industry. 

When Peter passed away

After Peter Dobelin passed away in December 2002 Isolde Dobelin convinced BSc Mech. Engineer Kurt Johannsen to take over the training of the OTTC Ammonia Diploma Qualification.

He continuously extended and upgraded the training always to the latest standard of technology.

So far we have over 400 graduated OTTC Ammonia Diploma holders working all over the world.

The OTTC Ammonia Diploma consist of a 6 week intense theoretical and practical (on our training plant) program.

Every course is 1 week AM-1, AM-2, AM-P1, AM-P2, AM-Diploma and AM-SH.

Safe Handling of Ammonia, also invented by OTTC in 2004 by BSc Mech. Engineer Kurt Johannsen, registered at SAQA for accreditation with ACCRICSA and later with SARACCA for the license to work on ammonia plants.

Every Friday learners write a test, with a pass mark of 60% and 75% is required for the diploma.

All testing is done individually by each course participant. (No team testing).

OTTC Ammonia Diploma

Featuring the OTTC Ammonia Diploma.
It consists of a 6 week course, inc AM 1, AM 2, AMP 1, AMP 2, AM 3-DIP and AM/SH/ASS.

Ammonia Diploma
refrigeration training
Extra curricular learning
refrigeration course
The Students Performed Excellently
Refrigeration Training
Isolde Loves Refrigeration
Air condition training
Education Through Practice
Excellence Through Training
ammonia training
Best Ammonia Diploma


Developing our skills together

Our family of educators encourages each student to team up to enjoy project work as we want all our students to walk away proud.

To have learned and achieved the goals we set out together.

refrigeration course

We Want To Say
"Thank you!"

This “thank you” follows all of our students home and abroad and sends you the best of wishes – you have been both aspiring students and good people.