Overview
This article provides a step-by-step guide for replacing the air dryer on an N2 Blast FPS3250–50000 unit. The dryer is the grey box at the base of the unit, with two air hoses and an electrical connection at the rear.
Important: A qualified electrician is required for the electrical disconnection and reconnection steps.
1. Power down the unit
On the HMI screen, press and hold the green button until the unit switches off.
2. Bypass the N2 Blast unit (if applicable)
If bypass valves have been installed to allow a complete bypass of compressed air to the N2 Blast unit, move the valves to bypass the N2 Blast.
3. Remove the front panel
Unscrew the 4 screws on the front panel. Lift the door off and set it aside. You should now see the internal components of the unit.
Note: The dryer is the grey box at the base of the unit. It has two air hoses connected at the back and an electrical connection behind an access panel at the rear of the dryer.
4. Depressurize the air supply
Isolate the incoming air supply to the unit. While wearing appropriate ear and eye protection, slowly open the black-handled air dump valve (to the right of the filter assembly in the above image). Air will discharge from the open end of the line. Wait until the air pressure decays and no more hissing can be heard.
5. Unbolt the dryer from the base
Locate the 4 mounting studs/nuts underneath the dryer that secure it to the base of the unit. Use a 7/16” or 11 mm socket to remove the 4 nuts.
Once the nuts are removed, the dryer can be slid forward.
6. Pull the dryer forward and disconnect the drain
Carefully pull the dryer unit forward to access the rear of the dryer. Disconnect the drain tube of the dryer from the rear of the N2 Blast unit.
7. Disconnect electrical connections (qualified electrician only)
At the rear of the dryer, locate the electrical access cover plate. Remove the top and bottom screws on the cover plate to access the terminations. The L, N, and E terminations will now be visible. A qualified electrician should disconnect the wires from the screw terminals.
8. Disconnect the air hoses
With the dryer pulled forward and power disconnected, disconnect the air hoses:
Option 1: Disconnect the air hose connections at the rear of the dryer while it is pulled forward. Option 2 (if more access is needed): Disconnect the hoses at the far ends of the air lines (opposite the dryer), which will allow the dryer to be completely removed from the unit. This provides more space to work on the hose connections.
Once hoses are disconnected, remove the dryer from the unit.
9. Reinstalling the dryer
Installation of the new or refurbished dryer is the reverse of removal:
Position the new dryer at the base of the unit. Reconnect the air hoses in the same locations/orientation as removed. Reconnect the drain tube to the rear of the N2 Blast unit. A qualified electrician should reconnect the L, N, and E electrical terminations and reinstall the access cover. Slide the dryer fully into position and reinstall the 4 mounting nuts underneath the unit. Close the air dump valve and restore the incoming air supply. Reinstall the front panel with the 4 screws. Power the unit back on by pressing and holding the green button on the screen until the unit starts.
Notes
Always follow local electrical and safety regulations. Ensure all connections (air, drain, and electrical) are secure before returning the unit to service. After replacement, observe the system for any unusual noises, leaks, or alarms.