Troubleshooting Guide - Hoffman Controls 890-DSQ Series Complete Installation & Operating Instructions

Condition
1. Improper installation, sequencer not wired correctly.
2. Sequencer's relay stages have not been selected.
Relay Stages Will
Not Activate 3. 0-10 VDC Input selected
4. Sequencer has been damaged
1. Incorrect sequencer input selected.
Relay Stages
2. Incorrect set point values used.
Not Activating
3. Incorrect relay sequencing mode selected.
Correctly
4. Secondary set points accidentally activated.
1. Variable speed EC Motor not wired correctly.
2. Selected EC motor is not a continuously variable speed motor.
Variable Stage's
3. Variable Stage operation not selected.
Variable speed
4. PWM operated EC motor wired to VDC output.
EC Motors Will
5. 0 - 10 or 10 - 0 VDC operated EC motor wired to PWM output.
Not Operate
6. EC Motor "OFF" on internal overload.
7. EC Motor not wired correctly. Sequencer damaged.
1. 10-0 VDC operated EC motor being used.
Variable Stage
2. Variable stage to fixed stage ratio number incorrect
EC Motor Will
Not Modulate
3. EC motor not loaded correctly
Properly
4. PWM operated EC motor being used.
1. Improper installation, sequencer not wired correctly.
2. Incorrect master computer port selected.
3. Modbus GND wire not connected
Modbus Operation
Not Working
4. Incorrect slave address, baud rate or parity selected.
Properly
5. Incorrect set points chosen (primary or secondary).
6. Micro controller substituting set points for "incorrect" value.
2463 Merrell Road, Dallas, Texas 75229 • Phone: (972) 243-7425 • Fax: (972) 247-8674 • Toll Free: 1-888-HCC-1190
www.hoffmancontrols.com

Troubleshooting Guide

Cause
|
Hoffman Controls
20
Solution
1. Check wiring, review instructions.
2. Select number of fixed relay stages used.
3. Deselect 0-10 VDC input
4. Replace sequencer
1. Select correct input source.
2. Input correct set point values.
3. Select correct sequencing mode.
4. De-activate secondary set points.
1. Check wiring, review instructions.
2. Use continuously variable EC motor.
3. Select Variable Stage operation.
4. Wire EC motor to PWM output.
5. Wire EC motor to VDC output.
6. Motor protected.
7. Replace sequencer.
1. Set percentages for 10-0 VDC operation.
2. Recalculate / use correct ratio number.
3. Use proper fan blade.
4. Use correct control signal.
1. Check wiring, review instructions.
2. Select correct port.
3. Install / connect GND wire
4. Select correct slave address, baud rate &
parity.
5. Chose correct set points.
6. Correct set point values.
Form: 173-0261-001 Rev G