Camus Hydronics DFH500 Installation, Operation And Service Manual

Also see for DFH1100: Installation, operation and service manual

Contents

Camus Hydronics DFH500 Installation, Operation And Service Manual Manual pdf 28 page image

25in the electrical enclosure across the contacts to be usedfor connection to the remote operator. The fixed auto re-setlimit is set to 230°F. In addition to the auto reset limit thefactory installs a manual re-set limit set to 250°F. Thecontrol provides pump operation. Staging operation isprovided by an external sequencing control. Heat demandis provided to the external sequencing control. Externalsequencing control then provides heat demand to thecontrol. Each control turns on its respective appliance pumpand stage 1 contact whenever an external heat demand ispresent. Once the external heat demand is removed fromthe control, the control turns off the stage 1 contact andoperates the pump to provide purging. Once the purgeperiod is complete, the control turns off the appliancepump.CAUTIONIf this setting is inadvertently chosen the appliance willcycle on the limits. There is a danger of scalding if thissetting is used in a DHW application.6.2 MODULATING SIGNAL GENERATORThis controller is located below the appliance temperaturecontroller. Once a call for heat has been initiated by theappliance temperature controller this control generates amodulating signal (4 – 20 mA or 2 – 10 VDC) based onreturn water temperature. After completion of factorysettings the lock feature permits adjustment of set pointonly (SV). This setting is normally 5ºF below the appliancetemperature controller setting. In this way the firing rate ofthe boiler will be at minimum when return watertemperature is 5ºF below target. The modulating signalgenerator has separate settings for domestic and hydronicsapplications and is factory set as shown below:Table 13DOMESTIC HOTWATERHYDRONICHEATINGP-n1 0 0P-n2 1.0 1.0P-df 1.0 1.0P-SL 32 32P-SU 160 220LOC FEATURE: 1 - locks in all settings 0 - allows adjustments to all settings 2 - allows adjustment of set point only6.3 VARIABLE FREQUENCY DRIVE (VFD)The VFD has a factory set security code which has to beentered before any adjustments can be made. The VFDhas 50 parameters, which can be adjusted. At present onlythe following are pertinent:Table 14Parameter# Function Settings2 Carrier Frequency 034 Stop Method 035 Standard SpeedSource04 (03 for 2- 10VDC)19 Acceleration Time 120 sec20 Deceleration Time 60 sec28 Fixed Boost 1.036 Preset Speed 2938 Skip Bandwidth 3.045 Speed at MinimumSignal32 (25 forcondensing)50 Fault History View Only51 thru 58 Miscellaneous View OnlyPART 7 COMPONENTS7.1 HOT SURFACE IGNITER (GLOW BAR)The silicon carbide igniter is inserted directly through thefan flange and held in place by two screws. A hold downbracket as well as sealing gasket above and below theigniter assures a good seal. Care must be taken whenremoving and/or installing the igniter since the siliconcarbide element is brittle. Always remove the igniter prior toremoving the fan assembly for inspection of the burner andheat exchanger. Properly prepared igniter will have a beadof silicone sealing the end mounting bracket to the ceramicshaft.Figure 18 – Hot Surface IgniterDuring trial for ignition a properly operating igniter willgenerate 3A which is the proof current required by theignition module for reliable and consistent operation. It isrecommended that the hot surface igniter be replaced every4,000 hours of appliance operation to maintain peak ignitionefficiency.7.2 FLAME SENSORThe flame sensor is inserted directly through the fan flangeand is screwed into the fan flange. Care must be taken,when installing the flame sensor, to align it perpendicular tothe fan flange and parallel to the burner tube and not toover tighten. Always remove the flame sensor prior toremoving the fan assembly for inspection of the burner andheat exchanger.Figure 19 – Flame Sensor