top of page



•Chilled water systems

•Air conditioning systems, both single and multi-zone

•Package rooftop cooling systems

•Restaurant refrigeration systems

•Complete insulation services

Fire Protection

JMSI  has a design department that offers various levels of layout service to meet our customers different needs as listed below


•Bid drawings that can include back up specifications, and water analysis calculations.


•Fire Sprinkler Fabrication / Installation / Coordination / Drawings include computer generated shop drawings, hydraulic calculations and materials submittals.


•Fire Pump and/or Ground Storage Tank installation and drawings with all associated piping and equipment.

Consulting Services/Construction Management             

JMSI  offers a complete range of services from design,  installation and commissioning.  Project scopes include contracts worth  $10,000.00 to $30,000,000.00. 


JMSI  has extensive domestic and international experience.  We pride ourselves on being able to handle anything from simple and small homes to difficult and challenging powerhouses in faraway places such as Yemen and the Dominican Republic.


JMSI  resources include seasoned engineers and professional tradesmen who are committed to producing quality results for its clients.  We are experienced in serving both the private and public sectors, either as a prime or sub-contractor.  We enjoy and work well in team-player scenarios, especially in multi-national global projects


JMSI  is a full service electrical contractor serving throughout Guam.

JMSI  is also a multi service electrical contractor that can offer clients broad capabilities support by experienced and qualified personnel.

We are experienced in site lighting, power distribution, fire alarm systems, industrial controls, lighting control systems, distribution systems and reliability centered preventive maintenance services

Preventive Maintenance

Preventive Maintenance programs have been proven in the industry to reduce yearly maintenance cost.

Reduce your utility costs, add years to your equipment life cycle.


We offer Preventive Maintenance for the systems below:


•Air Conditioning Systems

•Pump Systems

•Lighting Systems


JMSI  is a full service mechanical contractor serving customers throughout Guam.  People when asked will tell you that the most important factor in a major purchase is price.  Recognizing this, we put our mechanical staff to work exploring workable options and solutions to fit within your predetermined budget.  We have some of the best project managers, engineers and technicians in the area.  At the construction stage, the fact that so many of the skills required are “in-house”, makes the job coordination easier, helping to ensure that your project comes in on time and on budget. 


No matter the size of your company or the nature of your business, your mechanical systems can have tremendous impact on your bottom line.  However, this kind of risk can be greatly reduced through proper system design and maintenance.  We would be pleased to perform a no charge maintenance audit of the mechanical equipment in your building(s) in order to help you determine the level of service you require and the suitability of your equipment to the task at hand.


  We provide in house AutoCAD services with our engineers and project managers with extensive design assist experience.

JMSI Group of Companies








•Coordination Studies

•Project Feasibility

•Cost Analysis



Value Engineering             

At JMSI, we realize that time is money, and that build-ability is fundamental to true economy in construction.  We focus our attention on structural systems and simple details, which has put our service in demand.  Where difficult engineering problems have required a creative solution, we have been the innovator, and use simple, tried and proven techniques wherever they are available.

Research and Data Reports      

Data records - single and three phase voltages, current/amperages, power factor and kilowatts hours.



Power finder circuit seeker-locate and identify circuit not marked on electrical load centers and other electrical equipment.



JMSI Group of Companies is a team of highly motivated individuals dedicated to the Development, Management and Execution of Diversified Mechanical and Electrical Contracting characterized by Superb Quality and Economic Viability.  Our strength is generated by our commitment to Our Clients, Our People, Our Industry, and Our Communities





For any inquiries, questions or commendations, please call: Guam (671)646-6939 & Saipan (670)488-0484 or fill out the following form


To apply for a job with JMSI Group of Companies , please send a cover letter together with your resume to:

Success! Message received.

JMSI Group of Companies

Guam Office:

Physical Location: 

380 C East Harmon Industrial Park Rd.

Tamuning, Guam 96913

Mailing Address:

P.O. Box 9668

Tamuning, GU, 96931

Saipan Office:

Physical Location:

Chalan Kiya Industrial Center,

Warehouse NO. 5B

Saipan, MP, 96950

Mailing Address:

PMB 1014 Box 10000

Saipan, MP, 96950


bottom of page