Variable Speed-Rotary Screw Air Compressors[1].docx

The Maine Military Authority is requesting bids to supply; two (2) Variable Speed, Rotary Screw Air Compressors within approximately 30 business days of a signed contract or purchase order. Supervise installation of units, troubleshoot, and provide 2 hour of onsite instruction to the Owner's Representative in the care and operation of the system. All demolition, piping, electrical connections and other equipment to be provided under a separate contract.

Please provide data sheets for proposed equipment.

PRODUCTS;

VARIABLE SPEED DRIVE, ROTARY SCREW AIR COMPRESSOR

A. Fully enclosed, air-cooled, fluid-flooded variable speed rotary screw compressor with a capacity of 738 cfm at a full load pressure rating of 100 psig. This compressor shall be capable of full load operation from 75 to 150 psig with a maximum pressure capability of 150 psig.

B. Airend. Minimum design rating of main bearings shall be 100,000 hours.

C. Drive motor.

1. The main drive motor shall be 150 nameplate horsepower rated for 460 volt, 60 cycle, 3-phase operation.

2. The motor must be serviceable at a local motor service center and replacement motors should be readily available.

3. The main drive motor shall have an ODP enclosure.

D. Cooling System.

1. The compressor shall be air-cooled.

2. Coolers shall be vertical draft radiator type coolers. The coolers shall be sized to maintain normal operating temperatures with ambient air temperatures as high as 115ºF.

3. An air-cooled aftercooler shall be included as an integral part of the compressor package. The aftercooler shall be sized to cool the discharge air temperature to within 15ºF of the ambient temperature.

4. A 99.9% efficient moisture separator and condensate trap shall be included.

5. Compressor Fluid.

a. The fluid used in this compressor shall be a full synthetic specifically designed for compressor use.

b. The fluid shall contain no chemical substances that would require it to be treated as hazardous according to the appropriate laws in effect at the time of sale. Used fluid shall be suitable for recycling along with other waste petroleum oil.

c. Fluid carryover into the downstream air system shall not exceed 3 ppm by weight with new separator elements.

d. A fluid filter shall be provided with a minimum 12 micron absolute rating. The filter media must be micro-fiberglass. Paper media will not be accepted.

E. Compressor controls.

1. The compressor controls shall allow for pressure based, speed control to match compressor capacity to system demand. A true PID loop control function shall be utilized to control compressor speed/output in response to the changes in the pressure process variable. Operating pressure setpoint shall be easily adjusted in 1 psi increments.

2. If system demand should fall below approximately 20 percent of compressor capacity, the compressor shall operate in a start/stop mode. The compressor shall automatically reload/restart if the system pressure falls below the set point. Start shall be accomplished to minimize in-rush current draw and quickly bring compressor to speed to match system demand.

3. Control monitor shall be provided to display:

· Compressor discharge temperature

· Discharge air pressure

· Compressor set pressure

· Power on

· Running hours

· Compressor fault / alarm indication

4. The controller shall be constructed so that optional connections for remote annunciation can easily be made.

5. The display shall include a list of and status to indicate the following maintenance and shutdown conditions:

· High discharge temperature shutdown (Probes must be provided at the compressor discharge and the air/fluid separator reservoir to monitor high temperature conditions)

· Motor overload (This should alert a motor overload for all motors on the compressor package)

· Internal drive warning

6. The control panel shall provide operational data to view system dynamics.

F. Electrical controls.

1. All electrical controls shall be designed and constructed in accordance with National Electrical Code (NEC) guidelines.

2. The main drive control box shall be NEMA 1 design and contain starters for the main drive motor and fan motor along with other electrical controls.

3. All components within the main starter control box shall be UL approved or listed.

4. The main starter control box shall be UL approved or listed.

5. Remote mounted drive/starter control panel boxes will not be accepted.

G. Safety system.

1. A pressure relief valve shall be provided. This valve shall be sized to handle the full capacity of the compressor. It shall have a single, directed outlet. Multidirectional valves will not be accepted.

2. A high air/fluid temperature shutdown system shall be provided. This system shall operate with a minimum of two temperature sensors. One sensor must be located directly in the discharge air stream of the airend. One sensor must be located on the dry side of the air/fluid separator element. This system must be designed to prevent the compressor from running with a failed sensor.

H. Enclosures and Sound levels.

1. The compressor shall have a full metal enclosure with quick release panels for easy access to service and maintenance items.

2. Enclosed sound levels shall not exceed 75 dB(A) when measured in free field conditions, 1 meter away from the compressor.

I. Warranty To be included as standard offering; 1 year complete warranty on entire compressor. 5 year warranty on variable speed drive, motor, air/fluid reservoir, drive coupling, coolers. 10 year warranty on airend. Warranty should only require use of OEM parts and oil. Should any service be done by customer, it will not void or change warranty in any way.

J. Acceptable Manufacturers To be manufactured by Quincy, Ingersoll Rand or approved equal.

SCOPE

A. Submission of Effiency Maine Application data.

B. Store the equipment in a secure nearby location until called for by the Owner.

C. Coordinate with the Maine Military Authority for delivery and installation time and location.

This is in conjunction with Building Nos. 7220 & 7230 Compressed Air Systems, Limestone, Maine, Bureau of General Services Project #1785, A/E provided by Cordjia Capital Projects Group, LLC