Product: All Terminal Products
Subject: Adjusting Fan speed
Details:
RPM adjustments can be made on all terminal products with the ECM (blue) board.
Every IOM for terminal products has a section called (ECM overview and set-up) review that section to understand how to navigate the board.
NOTE: There are 44 different settings in the ECM board however only a few actually change the RPM’s.
Symbio/ UC400/ external 0-10 VDC with CSTI Option (Analog) or CSTI (Binary) 24v speed settings
Note Each unit has preset analog and binary RPM motor speed settings.
Binary 24v control
For 24V units, the first three speeds are High, Medium, and Low. TB3: 3, 4 and 5.
H1, MD1, and LO1 are for single-motor units.
H2, MD2, and LO2 would be set for dual-motor units.
Analog control
AHM1 and ALM1 control motor 1 analog signals (Symbio/UC400/External 0-10VDC w/ CSTI control option- red board).
For CSTI units the terminal block is TB4-2 = 0-10VDC input. TB4-3 is the DC common.
NOTE: TB4-1 = 10VDC output. Not used in most cases.
If the unit has 2 motors AHM2 and ALM2 would be preset as well.
Motor speed starts at 0.5 VDC (ALM1) and ramps linear to AHM1 RPM at 10 VDC.
E1M1 Setting DX or Electric heat
- DX or electric heat units lock RPM to high speed.
- These settings are E1M1 and E2M1. Units with two motors also use E1M2 and E2M2 settings.
- Turn off EHPT to adjust, but RPM settings are set for a reason.
- Prevent coil frosting.
- Avoid overheating electric heat elements.
- Only lower RPM after testing discharge air in DX or electric heat modes.
Every unit comes with a sticker with the serial number and some parameters that can be changed- See Example from the IOM
NOTE: Do not change the other settings unless you talk with technical support about the impacts to performance
Procedure to change fan speed for high speed:
- Does the unit have electric heat or DX?
- Yes: step 2.
- No: skip to step 4.
- Are you sure changing the RPM won't frost the coil or exceed high limit?
- Yes: Step 3 turn off EHPT function and adjust RPM settings
- No: contact your supervisor for approval.
- Turn off LRTP:
- Hold set button until H1 appears.
- Press minus button 4 times until LRPT appears.
- Press set button once (should be ON).
- Press minus once to turn OFF.
- Hold set until LRPT appears.
- Press set once to confirm OFF.
- Adjust high speed RPM: (24v binary)
- Hold set until H1 appears.
- Press set once to show current RPM.
- Change RPM as needed.
- Hold set until H1 appears.
- Press set once to confirm changes.
- Analog RPM adjustment for high speed: (Symbio/ UC400/ external 0-10 VDC)
- Hold set once.
- Press plus until AHm1 appears.
- Press set once to show current RPM.
- Adjust RPM as needed.
- Hold set to save (AHM1 appears).
- Press set once to verify changes.