INSTALLATION, OPERATION AND MAINTENANCE MANUAL FOR DJM3 MODEL 3.2 and 3.3 Modulating Burner Control INDOOR AND OUTDOOR MODELS UNIT MODEL NO. ____________________________ UNIT SERIAL NO. ____________________________ SERVICED BY _______________________________ TEL. NO: ___________________________________ CANADIAN HEAD OFFICE AND FACTORY 1401 – HASTING CRES. SE CALGARY, ALBERTA T2G 4C8 USA HEAD OFFICE AND FACTORY rd 32050 W. 83 ST.
DJM3.2 MANUAL TABLE OF CONTENTS Page I. II. III. APPLICATION ............................................................................................................ 1 SERVICE..................................................................................................................... 1 GENERAL DESCRIPTION ......................................................................................... 1 Basic Features ...................................................................................
DJM3.2 MANUAL TABLE OF CONTENTS Page BMS Calibration..............................................................................................................................16 Ambient Reset (continuous blower operation only).............................................................. 16 Make/Break Resets and Overrides ...............................................................................................17 XVIII. CALCULATED SET-POINT READOUT (Base Plus Calculated)..........................
DJM3.2 MANUAL TABLE OF CONTENTS Page Speed Sensor Values.....................................................................................................................37 Pre-purge Light Coming On (when not supposed to)........................................................................37 Constant Purge Light, No Ignition Attempt .................................................................................37 Failed Operation or Solid State Control Contacts by Others ...........................
A DJM3.2 MANUAL MODEL DJM3.2 and 3.3 If you note errors or omissions, please contact Wade Pascoe at (403) 287-4775 or Fax (403) 287-4799 or (243-5059). To ensure warranty is honoured, only a qualified HVAC service person, which has received training on the DJM3, should be employed for service and troubleshooting. If further information is required please contact the nearest Engineered Air office. NOTE: The DJM3.2 is similar to the rest of the DJM3 control family, the addition being the DJM3.
A NOTE: DJM3.2 MANUAL The discharge temperature requirements can be modified with the use of certain "reset" devices. The gas valve's opening curves are programmed into the DJM3.2's logic. All air and gas control is done electronically to simplify burner set up and eliminate the need to adjust troublesome mechanical air/fuel linkages. The DJM3.2 is a stand alone control device designed to provide most of the control requirements for a heating only unit. The DJM3.
A DJM3.2 MANUAL C. Damper operation: • Dampers are closed at night. 10. The DJM3.2 can be converted from standard to high turndown DJ burner simply by cutting a jumper wire on the back of the control. 11. Can be used with up to a 0.6 HP combustion motor. 12. Easier burner set up. 13. To reduce ground isolation problems, optical isolation was added to the digital and BMS inputs (+ and Β). 14. There are many standard service and testing features.
A DJM3.2 MANUAL are met. (Example: heat switch turned on.) NOTE: During “Service Mode” operation or safety operation, this step is ignored. 2. When a heating call is received, and before the combustion air blower is allowed to start, the combustion blower tachometer checks for a false signal. If no signal is present, the combustion air blower starts. 3. After the combustion blower starts, the DJM waits until the blower reaches pre-purge speed. 4.
A DJM3.2 MANUAL VI. SYSTEM TIMINGS Pre-purge seconds 45 Maintained purge DAY = 4 minutes, NIGHT = 1 minute Blower start delay Damper open time = 30 seconds Burner warm up time 30 seconds Burner cool down time 1 minute Heat exchanger cool down time 1 minute nominal Auto Low limit Bypass (from blower start) 5 minutes Also resets on change to day or night 5 minutes L/L trip timer activates for 30 seconds before lockout (NOTE: L/L is activated by dipswitch 8.) Flame fail 90 seconds VII.
A DJM3.2 MANUAL Main Board Pots Located on the Right Side of the DJM3.2 and 3.
A DJM3.2 MANUAL If the combustion blower IS RUNNING and the tachometer signal is absent, weak, or grounded. With a digital AC voltmeter, measure the AC volts present on terminals “YS to G”. When the combustion blower is running there should be 4 to 6 VAC present. If the AC voltage IS NOT PRESENT, check the tachometer sensor to magnet gap. It should be 1/16 to 1/8 inch. If the gap is OK, replace the speed sensor.
A DJM3.2 MANUAL status changes (on/off or off/on transition) or when the "SA" (supply air blower) contactor is energized or FS status is changed to on/off. A 30-second anti-noise low limit bypass timer is started every time a low limit condition is detected and the 5-minute auto bypass timer has timed out. This timer is designed to prevent nuisance low limit lock outs caused by any electrical noise which may be picked up by the discharge sensor.
A DJM3.2 MANUAL If the heat switch is on and there is an immediate heat call or a heat call within the first minute of the blower starting, the blower will shut off or remain off until the burner has been running for 30 seconds. If during this time the heat call is lost, the blower will cycle back on but the pre-purge will continue (Under some conditions, the supply fan may cycle a few times before the heat starts).
A NOTE: DJM3.2 MANUAL There is an optional room thermostat operation using a standard make/break thermostat for room sensing in place of the modulating control. For information on this option refer to this guide under "Make/Break Thermostat operation". XII. BASIC BURNER OPERATION The following controls the DJM3 burner: • • • If the DJM3 is not satisfied, it calls for heat. Contacts 4-2 close to energize the flame supervision control. The flame supervision control starts the pilot.
A DJM3.2 MANUAL The Optional Reset Inputs These may be controlled from room temperature, ambient temperature, voltage, or current input. The voltage and current inputs will only reset the discharge air calculated set-point (SPC) in the up direction. The room and ambient temperature resets will reset SPC in both directions. To use any resets, the DJM3.2 must be properly wired and configured.
A DJM3.2 MANUAL • With dipswitch 3 "on" the DJM3.2 operates as discharge control WITH room reset during the day when the blower is operating continuously. At night when operating from the room thermostat, the blower is operating intermittently. (Dipswitch 3 on.) • With dipswitch 3 "off " and the control in "day" operation (no power on terminal “K”), the DJM3.2 operates only on Discharge control. There is no room reset being allowed from the room thermostat.
A NOTE: DJM3.2 MANUAL If room reset calling, the “calculated” discharge temperature set-point will vary from the setting of “master” set-point. • • The room-reset feature is activated by dipswitch 3. Room sensor calibration pot is Pot Room Cal. • • Reset ratio pot is Pot Reset Ratio (refer to table below for values). Room reset band is ±3ºF (fixed). The “room reset band” means a room temperature error of just 3ºF will result in a maximum reset of the discharge air set point.
A Discharge Set-Point 15.5ºC 60ºF 21ºC 70ºF 27ºC 80ºF 32ºC 90ºF DJM3.2 MANUAL Pot #5 Setting Maximum Temp. ºC Minimum Temp. ºC Reset Band Width ºC Maximum Temp. ºF Minimum Temp. ºF Reset Band Width ºF 1 25 (+9.5) 12 (-3.5) 13 77 (+17) 54 (-6) 23 2 26 (+10.5) 11.5 (-4) 14.5 79 (+19) 53 (-7) 26 3 28 (+12.5) 10.5 (-5) 17.5 82 (+22) 51 (-9) 31 4 33 (+17.5) 9 (-6.5) 24 91 (+31) 48 (-12) 43 5 38 (+22.5) 9 (-6.
A DJM3.2 MANUAL Multiple Room Sensors Four sensors can be wired to give an average reading of room temperatures to the TRAC control. They must be wired in a series/parallel arrangement. The drawing above drawing shows a circuit making use of the built in sensor in the TE6100 Johnson Sensor/Setpoint assembly and using TE6000 sensors for the other three. (The other three could also be TE6100, just using the sensor wires .
A DJM3.2 MANUAL BMS RESET FROM VOLTAGE APPLIED TO + AND Β Current Reset Voltage (MA) (VDC) 0 3 3 5 4 12 6 7 16 8 9 20 10 Calculated Set-Point ºC ºF 13 55 13.5 56 14.5 58 16 61 18 65 20 68 23 75 26 79 BMS Calibration Apply 100% ma or voltage signal to the DJM3.2 “+” and “Β” terminals (i.e. 10 VDC or 20 ma). Record the settings of dipswitches 1, 2, and 3. Turn off dipswitches 1, 2, and 3. Measure the DJM3.2 calculated set-point. (DC voltage across resistor R124.) Turn dipswitch 1 on. Measure the DJM3.
A DJM3.2 MANUAL 25ºF the reset is at maximum. The high point of the slope is represented by (***), while (###) represents the low end. The second slope, the modified one, shows the results if a 120-ohm resistor is placed in series with the ambient sensor. When this is done the outside ambient must be colder before the reset begins to reset the discharge temperature higher. (**) Represents the high end of the slope while (##) represents the low end.
A NOTE DJM3.2 MANUAL If this system is to be used as a night heat package with the room temperature being set back to a lower value then that used in the daytime, this system would require a separate night thermostat and a device switching between the day and night thermostats. Sample wiring for “OR/V” follows: HOT NEUTRAL E C DM DM DM SA C1 FAN FS Μ LL Air Flow Switch N AS 2 HS 1 Q 3 IGN.
A DJM3.2 MANUAL temperature for each of the main values for the discharge set-point and Pot Reset Ratio settings. When using this reset system the discharge temperature will modulate to maintain the minimum or maximum, and will not operate at the discharge set-point. DIPSWITCH 3 MUST BE ON TO ACTIVATE THIS FEATURE. CONNECT “S” TO “SP” IF REQUIRED (to activate set-point on DJM3.2).
A DJM3.2 MANUAL selected discharge temperatures we chose above is 85 - 56 = 29º band width. Referring to the chart found in the "Set-Points" section and looking at the "Discharge Set-Point" of 60°F, note that the minimum is 54ºF and the maximum is 77ºF. The band width is 23º. Our calculations above noted we need a bandwidth of 29º. Therefore peruse down the band width column until you find a width close to 29º with a minimum discharge close to 56ºF and a maximum discharge close to 85ºF.
A DJM3.2 MANUAL 3. Linear Ambient Reset (during day and night) – Room Control with Intermittent Blower (also refer to Page 16) During day operation the discharge temperature will be linearly reset based on the ambient temperature. Dipswitch 2 MUST BE ON.
A DJM3.2 MANUAL DAY OPERATION • • level(s) 1 and 2 thermostats open Disc. Set-point = dial - max. down reset S SP Y Connect S to SP if required to use setpoint dial LEVEL 1 THERMOSTAT CLOSED • Discharge set-point = dial + max. up reset X Level 1 Thermostat Z LEVEL 2 THERMOSTAT CLOSED • discharge temperature = 120ºF V Level 2 Thermostat OR 6.
A DJM3.2 MANUAL SET-POINT READOUT AND DISCHARGE TEMPERATURE FROM VOLTAGE ON READOUT PINS (diagram follows) Voltage (VDC) ºC ºF 1 10 50 1.5 15 59 2 20 68 2.5 25 77 3 30 86 3.5 35 95 4 40 104 R29 is the discharge temperature reading R124 + R29 + R124 is the calculated set-point reading With the voltmeter set on the 20 VDC scale measure the DC voltage across R29 (the negative meter probe goes to the resistor lead closest to terminal Q). The readings are based on 10ºC per volt.
A DJM3.2 MANUAL NOTE: The readable range is 0 to 55ºC. At higher temperatures the reading accuracy is reduced. Typically at 50ºC the reading will indicate 2-3ºC lower than actual. XX. DISCHARGE/ROOM SENSOR READOUTS, CALIBRATION, ETC. TE 6000 Discharge Sensor Self-Test If the discharge sensor resistance is greater than 4000-ohms or less than 880-ohms, the unit will lock out either on low limit or bad temperature sensor. The DJM3.2 uses the discharge sensor for both temperature control and low limit.
A DJM3.2 MANUAL Discharge Sensor Calibration The discharge sensor this control is based on is the Johnson Control TE 6000-960, or equivalent. (Refer to diagram on Page 23.) Above is a chart to determine if the sensor itself is accurate. NOTE: These controls are calibrated at the factory and in most instances field calibration is not necessary. The discharge sensor is used for both temperature control and low limit safety control.
A DJM3.2 MANUAL = 10ºC scale as the temperature readout. This scale is fairly accurate from 15 to 25ºC. As temperatures approach 45ºC, the scale reads 2 to 4ºC below actual. NOTE: There are different calibration procedures for Johnson TE 6100 and the DJM3.2 face mounted set-point. Johnson Set Point While Set at 21°C 1. Measure the DJM3 set-point across Resistor R124 and adjust Pot Dis SP Cal (located next to terminal U) until the voltage reading is 2.1 volts. Built In Set-Point 2.
A DJM3.2 MANUAL XXI. DJM3.2 SET UP SHEET MAY 7, 1998 AUTO BYPASS LOW LIMIT dipswitch 8 ON____ENABLED OFF____DISABLED APPLICATION ____DOOR HEATER constant maintain purge dipswitch 7 ON ____OTHER (maintain purge time 4 minutes dipswitch 7 OFF) ROOM RESET ____Dipswitch 3 ON RESET RATIO POT RESET RATIO ____ 1=23°F, 2=27, 3=32, 4=44, 5=60 (approx. values) NOTE: The reset is bi-directional. The numbers given are for total degree of reset.
A DJM3.2 MANUAL Blower/Damper Operation The combination of energized night (K) and fan (FS) terminals set the blower and damper operation at night. DAY (FS on) Continuous Blower, Dampers Open, Discharge Control NIGHT (FS off, K on) Intermittent Blower, Dampers Off, Room Control ALTERNATE NIGHT OPERATION (HS, FS, K terminals all energized) Continuous Blower, Dampers Off, Discharge Control with Room Reset XXII.
A Pot 1 (located next to terminal G) is the curve matching pot. It is possible to use the DJM3.2 with several different Maxitrol valves. Each of these valves has a slightly different opening curve. The curve matching pot allows the DJM3.2 to be adjusted to control all of these valves. DJM3.2 MANUAL Top Board Bottom Board Pot Low Fire (located next to terminal 1) is the low fire RPM adjustment pot. This pot is used to adjust the low fire RPM (low fire air).
A DJM3.2 MANUAL NOTE: If combustion is not set correctly it can result improper burning which may produce products of combustion that smell, carbon and or an excessive amount of water in the flue. Care should be taken to set burners up properly. Note that temperature of the air and fuel may have a great affect on the set up you select. If both the combustion air and the fuel are at a constant temperature throughout the heating season, once combustion is set it should remain similar through the season.
A DJM3.2 MANUAL especially at higher flow. Series 20/M420, M520 and M620 (high turndown) As these valves have 2 low fire adjustments the following procedure should be followed carefully. Once the high fire pressure and combustion has been set up at point “B” above, turn the manual firing pot (fully CCW) to achieve low fire. Adjust the low fire RPM Pot Low Fire until the low fire speed on the combustion fan motor is 1250 RPM ±10 RPM (20.8 Hz) for 10:1 set up. (1195 RPM ±5 (19.91 Hz) for 15:1 turndown.
A DJM3.2 MANUAL 1195 RPM, 19.91 Hz.) Voltage to the series 50 valve should be 0 volts DC. Adjust the spring activated low fire adjustment at the top of the modulating gas valve (small screw) until an O2 reading of 16.8% to 17.5% is achieved. 9. Lock the low fire adjustment screw as described in point 7 above and then adjust the curve matching pot as in points 5 and 6 above. Type ES345D-L (high turndown) As this valve has 2 low fire adjustments the following procedure should be applied. 10.
A DJM3.2 MANUAL The low fire procedure set up is similar to that for the high turndown burners noted above. The difference is the maximum allowable CO at low fire is 200 PPM. The low fire O2 reading should be between 10.9% to 11.3%. The combustion slider is different than the high turndown slider. It is a plate that slides between the blower outlet and the burner box. The low fire RPM is adjusted using Pot Low Fire to 1850 ±10 RPM (30.5 Hz).
A DJM3.2 MANUAL NOTE: After set up is complete make sure to turn off dipswitch 5. Propane Gas Combustion set up for propane fuels for either the high turndown or the standard burner are similar to the above. The only modification suggested is it may be desirable to increase the oxygen settings by 1 to 1.5% above those for natural gas. Due to the quantity of fuel that can be drawn off a propane tank, it is often necessary to equip a propane fuel system with a vaporizer.
A DJM3.2 MANUAL Low Limit Lockouts NOTE: If your application does not require it, L/L could be disabled. If there is an intermittent problem with the discharge sensor, a false low limit lock out code may be generated. This happens if the discharge sensor generated an initial lockout and then the reason for the sensor lock out disappeared. (Refer to Section X for more detail on the low limit.) If the discharge sensor calibration is not correct you can also have low limit lockouts.
A DJM3.2 MANUAL likely find the supply fan off and the combustion fan off when you arrive at site. Note the condition of all of the lights. If you now turn the DJM3.2 power off for 30 seconds and then turn it back on, watch the lights as the ignition process retries. If an ignition or sensor problem exists it should be evident within a few minutes. If the combustion fan is seized, or the Hall Effect Speed Sensor is faulty, etc.
A DJM3.2 MANUAL “pre-purge problem” light may be flashing. Check the sensor location and magnet quality. Occasionally poorly manufactured magnets produce an irregular magnetic field. Sometimes reversing the magnet on the shaft will correct this problem (turning it around). Also refer to LED 2 for more info. If the test is done only for voltage and it proves to be correct, there could still be a problem as the DJM3 has a refined sensing circuit.
A DJM3.2 MANUAL plenum and the supply fan, delayed on, cannot remove the heat fast enough after it starts. The burner modulates off, as the discharge sensor is limited to 120ºF, 60 seconds later S/A goes off, and then combustion fan goes off. Room thermostat is still calling. Resolution 1. In night mode ensure that terminals “HS, K, and FS” are powered. This will make the supply fan operate continuously at night. 2. Turn dipswitch 7 on. This will place the DJM3.
A DJM3.2 MANUAL 8. Ensure there are no burrs or dirt in the pilot line orifice and air tube. These items have often been found with dirt, rust, insulation, paper, etc., blocking them. This includes checking the short connector at the blower housing where the rubber tube attaches. Also ensure no capacitor mounting screw is blocking the inlet to the pilot tube. 9.
A DJM3.2 MANUAL DJM3.2 Locks Up on Trial for Ignition When all regular troubleshooting items have been addressed about possible lockup problems, look at this possible problem. Some chips supplied to us in controls manufactured about mid 1995 that will lock up very shortly after the spark starts. This is often an intermittent problem and usually will have the DJM3.2 lock up without any lights on, however, some lights may be on in certain cases.
A DJM3.2 MANUAL cause occurs if a combustion fan motor is surging in its speed after the motor has been in operation for an extended period of time, it is likely that the “triac” is overloaded and is running hotter then design. When this occurs the surging is caused by the triac shutting down due to heat. The surging occurs at lower modulated speeds of the combustion fan and pulses about twice a minute.
A DJM3.2 MANUAL Water and Ice From Combustion These heat exchangers are very efficient. Water is one of the major products of combustion and as such must be controlled. The units are equipped with a drain. It is however best to allow water to leave the unit in the flue gases in vapor form. Combustion that is set at maximum efficiency will produce excess moisture. Often it is desirable to have 1% to 2% higher excess oxygen readings then those normally listed to assist in keeping the flue gases drier.
A DJM3.2 MANUAL 3. If there is a BMS system connected to the DJM3 determine if it is necessary to cut R43 before mounting the control. The best way is to look at the board you are removing. 4. The DJM3.2 uses a Johnson TE 6000 discharge air sensor. • Turn service switch 5 on to adjust the burner. • • • Adjust Pot Hi Service marked “SP” to high fire and set up the burner. Adjust low fire. Adjust curve-matching pot.
A • • • DJM3.2 MANUAL LOW FIRE COMBUSTION BLOWER SPEED at 10:1 turndown is about 1250 RPM ±10 RPM (20.8 Hz) at 15:1 turndown is about 1175 RPM ±10 RPM (19.91 Hz) HIGH FIRE COMBUSTION BLOWER SPEED is about 3400 RPM LIGHT OFF SPEED is about 2300 RPM Maxitrol Modulating Gas Valve Voltages The different Maxitrol valves modulate through about the following voltages: • • • • M650 or M651 M550 or M520 M450 or M420 MR212 2 2 2 2 - 13 VDC 12 VDC 11 VDC 11 VDC XXV.
NO FAN OPERATION ON DJM-3 Dip switch #5 should be in off position. 24 VAC on T1 T2 Yes No Is heat call light SOLID ON upon call for heat? Yes - Restore power - Check line voltage No Fan should start after 30 seconds Yes Fan will start 30 seconds No but fan doesn’t start No Yes Is 24 VAC on N to K terminals? Yes No Normal Operation Is 24 VAC on N to FS terminals? Yes If burner fires for 30 seconds but fan doesn’t start No Unit is in night mode and fan operation is intermittent.
NO HEAT ON DJM-3 The following is a flow chart covering many general operating/troubleshooting situations. If a more detailed manual is needed, contact the nearest EngA factory. LED ON 2 SEC. FLASH 1 SEC. FLASH LL Lockout Low Limit Bypass Discharge Sensor Open Prepurge Prepurge Problem Heat Call HT Switch Open Ignition Enabled Flame Failure Dip switch #5 should be off for this quick test.
ORIGINAL DJM-3.2 OR 3.3 WIRING CB CB P 1 3 MV MV VS CS G YS O M 4 + LED ON SA C LL 2 DM 1 LL LOCKOUT 2 SEC FLASH 1 SEC FLASH LL BYPASS D SEN OPEN 2 PRE PURGE PP PROBLEM 3 HEAT CALL HT SW OPEN 4 IGN ENABLE S D P I C S INT FLASH - Q + - D SEN CAL + - DIS SP CAL S SERVICE MODE FLAME FAIL BMS CAL -- DM U V + X Y ROOM CAL Z N + HS HI SERVICE K 20 FS 15 T2 DJM CONTROLLER T1 MODEL DJM 3.
