Daikin Microtech III — общее описание системы управления для чиллеров [7/44]

Содержание

• Control panel operating manual p.1
• Air cooled scroll chiller p.1
• Table of contents p.2
• Warning p.5
• Danger p.5
• Caution p.5
• Introduction p.5
• Controller operating limits p.6
• Two levels of security protection against unauthorized changing of setpoints and other control parameters warning and fault diagnostics to inform operators of warning and fault conditions in plain language all events and alarms are time and date stamped for identification of when the fault condition occurred in addition the operating conditions that existed just prior to an alarm shutdown can be recalled to aid in isolating the cause of the problem twenty five previous alarms and related operating conditions are available remote input signals for chilled water reset demand limiting and unit enable test mode allows the service technician to manually control the controllers outputs and can be useful for system checkout building automation system bas communication capability via lontalk modbus or bacnet standard protocols for all bas manufacturers pressure transducers for direct reading of system pressures preemptive control of low evaporator pressure conditions and pressure to take corre p.6
• Hardware structure p.7
• Controller description p.7
• General description p.7
• Communication modules p.8
• Controller and extension details p.8
• Controller architecture p.8
• Main controller p.9
• Options expansion module p.9
• Digital outputs p.9
• Digital inputs p.9
• Controller inputs and outputs p.9
• Analog outputs p.9
• Analog inputs p.9
• Exv module 1 p.10
• Analog inputs p.10
• Stepper motor output p.10
• Exv module 2 p.10
• Digital outputs p.10
• Digital inputs p.10
• Analog outputs p.10
• Stepper motor output p.11
• Digital outputs p.11
• Analog outputs p.11
• Set points p.12
• Set point tables p.12
• Sensor information p.12
• Pressure inputs will be read using 0 to 5 volt ratiometric sensors nominal voltage range will be 0 to 4 volts pressure on the low side will be measured using pressures from 34 kpa 5 psi to 2448 kpa 355 psi in the nominal voltage range pressure on the high side will be measured using sensor reading pressures from 29 kpa 4 psi to 4975 kpa 721 psi in the nominal voltage range p.12
• Pressure p.12
• All temperature sensors will be termotech ntc sensors reading 10k ω at 25 c with temperature resistance the steinhart hart coefficients for this sensor are as follows c1 is 1 25191e 03 c2 is 2 47363e 04 c3 is 8 51343e 08 p.12
• Actuator information p.12
• The electronic expansion valves used are danfoss supplied and all use the same bipolar stepper motor the stepper driver is configured as follows total steps 3810 movement speed 150 steps second acceleration 0 holding current 0 move current 140ma overdrive closed steps 100 p.12
• Temperature p.12
• Set points are stored in permanent memory read and write access to these set points is determined by a separate hmi specification p.12
• Set points are initially set to the values in the default column and can be adjusted to any value in the range column unit level set points p.12
• The following set points cannot be changeable unless the unit switch is off number of circuits number of compressors number of fans fan vfd enable lls valve enable double stpt enable lwt reset enable demand lim enable ext alarm enable p.14
• The circuit mode set points cannot be changeable unless the corresponding circuit switch is off the compressor enable set points cannot not be changeable unless the corresponding compressor is not running p.14
• Special set point operations p.14
• Some settings have different ranges of adjustment based on other settings p.14
• Proper amount of antifreeze must be applied p.14
• Note condenser target 67 and condenser target 33 will be available only when number of comps is 3 1 circuit or 6 2 circuits condenser target 50 will be available only when number of compressors is 2 1 circuit or 4 2 circuits p.14
• Exv position set point on each circuit follows the actual exv position while exv control auto when exv control manual the position set point is changeable p.14
• Auto adjusted ranges p.14
• Test mode set points p.15
• For unit level outputs test mode is enabled only when the unit mode is test for circuit outputs test mode is enabled when either unit mode is test or the circuit mode is test p.15
• All outputs are manually controllable via test mode set points only when test mode is enabled p.15
• 15 the following settings can be automatically set back to off after being on for 1 second clear alarms network clear alarms clear cycle timers clear ice timer stage delay clear p.15
• When the unit mode is no longer test all unit test mode set points are be changed back to their off values when test mode is no longer enabled for a circuit all the circuit test mode set points for that circuit are changed back to their off values p.15
• V type condensation is managed at unit level both circuits work with the same saturated condensing temperature more specifically with the higher of each circuit probe readings w type condensation is managed at circuit level each circuits works with its own saturated condensing temperature p.15
• Unit configurations p.15
• The table below summarizes the possible unit configurations p.15
• The compressor outputs are a special case and they are allowed to remain on for 3 seconds before being automatically set back to off p.15
• Lwt error p.16
• Unit states p.16
• Unit functions p.16
• Unit capacity p.16
• Staging temperatures p.16
• Pulldown rate p.16
• Lwt slope p.16
• Evaporator delta t p.16
• Control band p.16
• Calculations p.16
• Evaporator pump control p.17
• Power up start delay p.17
• Pump selection p.18
• Primary standby pump staging p.18
• Evaporator pump configuration p.18
• Unit capacity control will be performed as described in this section all unit capacity limits described in following sections must be applied as described p.19
• Unit capacity control p.19
• The lwt target varies based on settings and inputs the base lwt target is selected as follows p.19
• The first compressor on the unit is started when evaporator lwt is higher than the startup temperature additional compressors can be started when evaporator lwt is higher than the stage up temperature and the stage up delay is not active when multiple compressors are running one shut down if evaporator lwt is lower than the stage down temperature and the stage down delay is not active all running compressors shut down when the evaporator lwt is lower than the shut down temperature p.19
• The base lwt target may be reset if the unit is in cool mode and lwt reset is enabled via the set point the reset amount is adjusted based on the 4 to 20 ma reset input reset is 0 if the reset signal is less than or equal to 4 ma reset is 5 6 c 10 f if the reset signal equals or exceeds 20 ma the amount of reset will vary linearly between these extremes if the reset signal is between 4 ma and 20 ma when the reset amount increases the active lwt target is changed at a rate of 0 c every 10 seconds when the active reset decreases the active lwt target is changed all at once after the reset is applied the lwt target can never exceed a value of 15 6 c 60 f p.19
• Stage up delay p.19
• Lwt target p.19
• Leaving water temperature lwt reset p.19
• If auto pump control is selected the primary standby logic above is still used when the evaporator is not in the run state the run hours of the pumps will be compared the pump with the least hours will be designated as the primary at this time p.19
• Compressor staging in cool mode p.19
• Auto control p.19
• A minimum amount of time defined by the stage up delay set point passes between increases in the capacity stage this delay only apply when at least one compressor is running if the first compressor starts and quickly shuts off for some reason another compressor may start without this minimum time passing p.19
• Staging sequence p.20
• Stage up delay p.20
• Stage down delay p.20
• Next to stop p.20
• Next to start p.20
• Compressor staging in ice mode p.20
• Unit capacity overrides p.21
• Unit capacity limits can be used to limit total unit capacity in cool mode only multiple limits may be active at any time and the lowest limit is always used in the unit capacity control p.21
• Three compressors p.21
• The maximum unit capacity can be limited by a network signal this function is only enabled if the control source is set to network and the network limit option set point is set to enable the maximum unit capacity stage is based on the network limit value received from the bas and is determined as shown in the following tables two compressors p.21
• The maximum unit capacity can be limited by a 4 to 20 ma signal on the demand limit analog input this function is only enabled if the demand limit option set point is set to enable the maximum unit capacity stage is determined as shown in the following tables two compressors p.21
• Six compressors p.21
• Network limit p.21
• Four compressors p.21
• Demand limit p.21
• 22 four compressors p.22
• Unit condenser p.22
• The maximum rate at which the leaving water temperature can drop shall be limited by the maximum pulldown rate set point only when the unit mode is cool if the rate exceeds this set point no more compressors shall be started until the pulldown rate is less than the set point running compressors will not be stopped as a result of exceeding the maximum pulldown rate p.22
• Six compressors p.22
• Since proper staging up has to be assured for the circuit with the greater saturated condensing temperature if both circuits are on the have the same reference saturated condensing temperature that is calculated as the higher of each circuit saturated condensing temperature p.22
• Ref_sat_con t max t_sat_cond_t_cir 1 t_sat_cond_t_cir 1 p.22
• On units configured with single point power connections the maximum load amps could be exceeded at high ambient temperatures if all compressors are running on circuit 1 or all but one compressor on circuit 1 power connection is single point and the oat is greater than 46 c 115 f circuit 2 is limited to running all but one compressor this limit will allow the unit to operate at higher temperatures than 46 c 115 f p.22
• Maximum lwt pulldown rate p.22
• High ambient limit p.22
• Fans have to be staged as needed any time at least one compressor is running p.22
• Fan staging accommodates anywhere from 4 to 6 common fans using up to 4 outputs for control the total number of fan on is adjusted with changes of 1 or 2 fan at time as shown in the following table p.22
• Fan staging p.22
• Condensation is managed at this level when the unit is configured a v double circuit type what follows covers only this type of unit condenser control of other unit configurations included v single circuit is described in circuit functions chapter below in this document p.22
• If unit load is 50 and one circuit if off starting the application forces the unit load redistribution by mean of a staging down p.23
• For v double circuit unit further target adjustment is needed to face up possibly significant difference between circuits saturated condensing temperatures this can happen when unit load is unbalanced between circuits 25 75 or 50 with one circuit at full load and the other off p.23
• Condenser target p.23
• A minimum condenser target calculated on the base of evaporator lwt has anyway to be enforced p.23
• Unbalanced load management p.23
• Thus will be the maximum between selected set point and the calculated one p.23
• The standard unit capacity control logic provides the next off compressor to stop on the full load circuit and consequently the unit load will be rebalanced in this conditions there s no issues for further compressor start p.23
• The first fan will not start until the evaporator pressure drop or condenser pressure rise requirement for the no pressure change after start alarm is satisfied once that requirement is met if there is no fan vfd then the first fan turns on when the saturated condenser temperature exceeds the condenser target if there is a fan vfd then the first fan turns on when the saturated condenser temperature exceeds the condenser target less 5 6 c 10 f after this the four stage up dead bands shall be used stages one through four use their respective dead bands stages five through six use the stage up dead band 4 when the saturated condenser temperature is above the target the active deadband a stage up error is accumulated stage up error step saturated condenser temperature target stage up dead band p.23
• The condenser target is automatically selected from the set points see set points tables condenser target x basing on the actual unit capacity percentage compressors running total number of compressors on the unit each stage of capacity on a circuit uses a different condensing target set point p.23
• The condenser targe p.23
• Staging up p.23
• Is override as follows new condenser target condenser targe p.23
• In this condition to prevent a further compressor stage up from being inhibited the condenser targe p.23
• Staging down p.24
• Stage up compensation p.24
• Refrigerant saturated temperature p.24
• Evaporator approach p.24
• Condenser approach p.24
• Circuit functions p.24
• Calculations p.24
• Vfd state p.24
• Suction superheat p.25
• Pumpdown pressure p.25
• Compressor availability p.25
• Circuit states p.25
• Circuit enabling p.25
• Circuit control logic p.25
• Pumpdown procedure p.26
• Low ambient starts p.26
• Stopping a compressor p.27
• Starting a compressor p.27
• Fan staging p.27
• Cycle timers p.27
• Compressor control p.27
• Circuit status p.27
• Circuit condenser p.27
• The first fan will not start until the evaporator pressure drop or condenser pressure rise requirement for the no pressure change after start alarm is satisfied once that requirement is met if there is no fan vfd then the first fan turns on when the saturated condenser temperature exceeds the condenser target if there is a fan vfd then the first fan turns on when the saturated condenser temperature exceeds the condenser target less 5 6 c 10 f after this the four stage up dead bands shall be used stages one through four use their respective dead bands stages five through six all use the stage up dead band 4 p.28
• The condenser target thus will always be the maximum between selected set point and the calculated one p.28
• The condenser target is automatically selected from the set points see set points tables condenser target x basing on the actual unit capacity percentage compressors running total number of compressors on the circuit each stage of capacity on a circuit uses a different condensing target set point p.28
• Staging up p.28
• Condenser target p.28
• A minimum condenser target calculated on the base of evaporator lwt has anyway to be enforced p.28
• Vfd state p.29
• Staging down p.29
• Stage up compensation p.29
• Exv control p.29
• Auto control p.29
• Liquid line solenoid valve p.30
• High condenser pressure p.30
• Exv position range p.30
• Capacity overrides limits of operation p.30
• Alarms p.30
• Unit fault alarms p.30
• Pvm gfp fault p.30
• Manual control p.30
• Low evaporator pressure p.30
• Freeze temp sensor fault p.31
• Evaporator water temperatures inverted in cool mode p.31
• Evaporator water freeze protect p.31
• Evaporator lwt sensor fault p.31
• Evaporator flow loss p.31
• Unit problem alarms p.32
• Outdoor air temperature sensor fault p.32
• Option module comm failure p.32
• Low ambient lockout p.32
• Exv module 2 comm failure p.32
• Exv module 1 comm failure p.32
• External alarm p.32
• Evaporator pump 1 failure p.32
• Unit warning alarms p.33
• Pvm gfp fault p.33
• Low evaporator pressure p.33
• External event p.33
• Evaporator pump 2 failure p.33
• Evaporator ewt sensor fault p.33
• Circuit fault alarms p.33
• Bad lwt reset input p.33
• Bad demand limit input p.33
• Motor protection fault p.34
• Mechanical high pressure switch p.34
• Low oat restart fault p.34
• High condenser pressure p.34
• Evaporator pressure sensor fault p.34
• Condenser pressure sensor fault p.34
• No pressure change after start p.34
• Unit power restore p.35
• Unit events p.35
• Low evaporator pressure unload p.35
• Low evaporator pressure hold p.35
• Failed pumpdown p.35
• Events p.35
• Circuit warning alarms p.35
• Circuit events p.35
• 0 suction temperature sensor fault p.35
• Using the controller p.36
• The unit controller operation p.36
• High condenser pressure unload p.36
• Passwords p.37
• Navigating p.37
• In the right of the line and used to link to the next menu parameters with a value or adjustable setpoint p.38
• Navigation mode p.38
• Edit mode p.39
• Optional remote user interface p.40
• Basic control system diagnostic p.42
• Controller maintenance p.43
• Daikin europe n v p.44