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This troubleshooting guide provides solutions to issues with Emech control systems. Failure to remedy the problem could be result of serious problem in which case you should contact Emech Control.
Click here for pdf version of the troubleshooting guide (EOSN0003_RevA_Trouble Shooting Guide). Acrobat Reader 5.0 or later [available here] is required. To save locally onto your PC right click the link and select "Save target as...".
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Actuator display lights up intermittently, but does not move. |
| Is 24 Vdc power supply adequate? |
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The power supply does not have the required capacity. Review the power supply transformer rating with Section 4.0 in the G1 IOM. |
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| Is 24 Vdc supply stable at actuator terminals? |
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The power supply cables have an excessive voltage drop. Review cable rating with Section 7.2.2 in the G1 IOM. |
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Actuator dead (display not lit, no movement). |
| Key switch set to 'on'? |
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Key switch is 'off'.
Switch key 'on'! |
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| Is the fuse ok? |
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Replace fuse - if fuse blows repeatedly please contact Emech Control. |
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| Indicates serious problem - Contact Emech Control. |
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No communication when using EmechConfig. |
| Is Emech supplied serial cable properly connected at the PC and actuator? |
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Check for damage to connector pins, and connect serial cable properly. |
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| In EmechConfig, is the correct COM port selected from the COMS menu? |
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Wrong port may be selected.
Determine to which port on the PC the serial cable is attached. This is usually COM1 for notebook computers, unless using a USB serial adapter in which case COM4, COM5 or others are possible. |
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| Is actuator powered (display backlight is lit)? |
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Actuator is turned off. Power actuator, or check the section "Actuator Dead" in this guide if problems persist. |
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Actuator displays ‘E2’ when set Temperature Controller Mode. |
| Is temperature probe properly connected to the actuator plug? |
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Ensure probe is securely plugged into actuator. |
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| Replace temperature probe. Is the error still there? |
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Original temperature probe is damaged. |
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| Indicates serious problem - Contact Emech Control. |
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Failure to Reach Set Point. |
| Is valve closed (i.e. no flow) when the coupling visual indicator shows 'zero' position? (use positioner mode to move to 'zero' position). |
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Actuator shaft is not properly aligned with valve spindle. Move actuator to zero position. Remove actuator. Rotate valve stem so that the notch in points toward the cold port (on F3). Reattach actuator. |
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| Is actuator set to temperature control mode? (No leds, or led 1 only lit indicates temperature control mode). |
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Actuator is in positioner mode and will not respond to temperature changes at the outlet. Hold the MODE button and press the DOWN button to toggle into temperature controller mode. This will be confirmed by either no lit leds(deg C), or led 1 only lit (deg F). |
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| Is the manual override handle disengaged? (preventing motor movement). |
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Manual override is preventing the motor from moving the valve. Make sure manual override is pushed in (fully disengaged). |
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| Are water supplies cold / hot enough to achieve desired set point? Manually move the actuator to see if the desired temperature can be achieved. |
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Water supply temperatures are insufficient to achieve set point. Reevaluate set point requirement, or alter supply temperatures. |
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| Compare the Emech temperature reading with another thermometer. Does the temperature display match the displayed temperature? |
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Faulty / damaged temperature probe Contact Emech Control for a replacement temperature probe assembly. |
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| Is actuator properly configured for the valve? |
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Actuator may be setup for wrong valve. This limits its operating stroke and prevents effective control. Select the correct valve type in EmechConfig. Run Emech Config and check that selected config settings for the appropriate valve type (F2, F3, F4 etc). |
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Control is Unstable/Oscillates. |
| Does the outlet flow from the Emech valve meet or exceed the flow specified in the product manual for minimal stable temperature control? |
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Flow may be too low for stable control. The main options for preventing instability are:
1. Achieve higher flow (see Technical Data Section of Valve Manual).
2. Decrease control gains until control stabilises.
3. If appropriate, replace valve with a smaller model that can achieve stable control with lower flow. |
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| Are control gains set to higher than normal values? Standard is Proportional Gain = 200 and Differential Gain = -20. |
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Selected Control gains may be too high for application, try standard gain settings. |
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| Is there a large imbalance between supply pressures? |
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Pressure imbalance may be contributing to instability. Decrease control gains until control is more stable, or add pressure regulation to limit the imbalance. |
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Actuator does not respond as expected to REMOTE current loop signal. |
| Is Actuator set to receive a remote signal? (Indicated by REMOTE LED on the display panel). |
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Actuator is in LOCAL Mode and will not respond to REMOTE signal. Hold the MODE button and press the SET button to toggle into REMOTE mode. |
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| Is loop signal connected to the correct terminals on the Emech Actuator terminal block, and with the correct polarity? |
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Signal may be connected to the incorrect terminals or could be reversed. Connect signal to correct terminals. See Section 8 in G1 IOM. |
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| Is remote signal a powered loop signal in the range 4-20 mA ? (or 5-19 mA for active temperature control). |
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The signal source may be outside the Emech actuator's expected signal range. Check with a loop calibrator that the signal is within the specified range. See Section 8.1 and 9.3.3 in the G1 IOM. |
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