Nortec SE 100 Скачать руководство пользователя страница 106

Страница: 106 / 134

SETC Outdoor Specific Components

Mounting Panel
(External Disconnect)

Outdoor Cabinet

--...

Cabinet Drain ..........._

(Drain Pan)

lectrical Conduits

Outdoor Mounting Base

(With integral drain

pan)

,,...._

Lifting Hook (4)

Exhaust Fan

Freeze Protection Valve

Auxiliary Drain Outlet

(Freeze Protection Valve)

Figure 2: SETC Outdoor Humidifier Components

Содержание SE 100

Страница 1: ......

Страница 2: ......

Страница 3: ......

Страница 4: ......

Страница 5: ......

Страница 6: ...d Driver Board High Voltage Terminal Block Base Manual Drain Switch Transformer Total Controller Heat Exchangers Faceplate Steam Outlet Fill Box Vacuum Break Steam Inlet Boiler Steam Actuator Wye Strainer CV Valve Fill Valve Drain Outlet P Trap Condensate Drain Boiler Steam Auxiliary Drain Outlet Steam Trap Mixing Box Drain Pump ...

Страница 7: ......

Страница 8: ...SETC50 Note SE 750 has 2 steam outlets SE 525 750 SE 100 175 SE 1050 SE 250 375 ...

Страница 9: ......

Страница 10: ......

Страница 11: ......

Страница 12: ......

Страница 13: ...ft 30 cm min Pressurized steam supply Water supply 30 80 psig Plumbing Pg 14 Boiler Steam Pg 15 Condensate return to boiler Air gap Tank drain Controls Pg 23 Modulation Controls On Off Controls 1 24 VAC 2 On Off Loop 3 Ctrl Ground 4 Control Signal 5 Limit Signal 6 5 VDC 7 Ground 8 Tank Blow Down 9 Ground 10 Actuator 11 Actuator 12 0 10 VDC Out S E X T T C P Dedicated Circuit Breaker or Disconnect ...

Страница 14: ...r 30 in 76 cm Min SE 1050 only Mount Humidifier 5 95 Level 30 in 76 cm Min Side Clearance Condensate drain line must be sloped down do not use to lift condensate 30 in 76 cm Min Front Clearance 36 in 91 cm Min Top Clearance 0 in for SE50 only ...

Страница 15: ...sure humidifier is Level Fasten SE humidifier to stand with bolts lock washers and nuts provided Tighten to 200 in lb 22 6 Nm Note Center support only present on SE 525 and larger Secure stand to floor four places hardware by others ...

Страница 16: ...12 8 in 32 6 cm Anchor 3 8 in M10 support rods to ceiling by others Sloped drain 1 2 in pipe by others Support rods and hardware by others must not extend below support bracket flange ...

Страница 17: ...r gap required 2 1 2 in to 1 1 4 in copper reducer is ideal Hose line must not touch the bottom of the funnel Min 1 1 4 in OD drain line Slope down Increase size if combining multiple drains Axillary drain 1 2 in female NPT For draining tank without pump Leave valve closed except if freeze protection is installed Pipe unions and water shut off valve not supplied by NORTEC ...

Страница 18: ...ptional F T Trap Wye Strainer Isolation Valve Boiler steam inlet port see table 3 Condensate Drain Port see table 3 Condensate drain line Gravity feed to boiler Use pump if condensate must be lifted Note Nortec supplies CV valve actuator and wye strainer All other components and fittings by others Not pressurized condensate header slope down Pressurized condensate header ...

Страница 19: ...extension Actuator 2 turns then push in and 1 8 turn to lock Raise valve stem to full up 1 2 in 1 2 cm min CV Valve Install and tighten mounting nut Turn stem extension until holes line up Insert connecting pin Tighten jam nut againststemextension ...

Страница 20: ...Steam Direction Use Appropriate Slope Insulate Pipe 2 Degrees 0 5 in 12 mm 1ft 30 cm 1 in 2 5 cm pipe insulation 10 Degrees 2 in 5 cm 1 ft 30 cm ...

Страница 21: ...ertical to horizontal transitions 12 in 30 cm min drop to top of Trap Traps Use NORTEC 0 375 in condensate hose 1 4 in Med L copper tubing or 0 375 in stainless steel tubing Condensate drains must be sloped down Route to humidifier fill cup if possible as steam line ...

Страница 22: ... 5 cm min 1 ft 30 cm 1 ft 30 cm min before anybend Condensate line Trap To drain Use steam hose between steam outlet and steam line Calculated absorption distance to any obstruction or 8 10 ft 2 4 3 m if unknown 2 x duct height min 2 3 Duct height 12 in 30 cm min Mount distributor to side of duct ...

Страница 23: ...tributor Trap To drain 1 ft 30 cm min Trap To drain 1 ft 30 cm 0 5 in 1 2 cm min 1ft 30 cm min before any bend Obstruction 1 ft 30 cm min Use full size condensate tee at low point Slope lines up to and immediately after it Trap To drain Trap To drain Hose will soften over time proper support Is necessary ...

Страница 24: ...al Space 1 ft 30 cm min before turn Condensate tee every 15 20 ft 4 5 6 m Install condensate tee before distributor Condensate tee at low points Individually trap multiple condensate returns before joining on common line 1 ft 30 cm min To Drain ...

Страница 25: ...Fusing must not exceed max circuit protection as indicated on the specification label 2 Ensure that adequate power is available to carry full humidifier amp draw as indicated on the specification label 3 All wiring to be in accordance with national and local electrical codes Single Phase Supply Ground L1 Neutral Dedicated circuit breaker or fused disconect Ground L1 Neutral E I X N T T ...

Страница 26: ...10 ft min 1 2 3 Air Proving Switch Duct High Limit Humidity Control return air duct or in room ...

Страница 27: ...all mounted as shown or return air duct mounted Knockouts provided in top and bottom panels Install strain relief by others Air Proving Switch Duct High Limit Humidity Control Wire to make when sensing air flow 2548732 On Off Duct Humidistat Wire to make on drop in humidity 2548731 On Off Wall Humidistat or 2548732 On Off Duct Humidistat OR E S X E T 1 24 VAC 2 On Off Loop 3 Ground 4 Control Signa...

Страница 28: ... 5 The SEP can only accept one modulating signal Knockouts provided in top and bottom panels Install strain relief by others 2520266 Digital Duct Humidistat Package 1510142 Digital Wall Humidistat Analog Out 3 24 VAC 2 Ground 1 Connect 24 VAC terminal 1 of SETC P to terminal 2 of controllers Insert On Off controls or jumper between 1 and 2 1 24 VAC 2 On Off Loop 3 Ground 4 Control Signal 5 Limit S...

Страница 29: ...igital display as shown below wire digital display to humidifier as shown for 1510142 Digital Wall Humidistat Knockouts provided in top and bottom panels Install strain relief by others 2520261 Digital Wall W O Sensor 1509858 Wall Sensor Connect 24 VAC terminal 1 of SETC P to terminal 2 of controllers 1 24 VAC 2 On Off Loop 3 Ground 4 Control Signal 5 Limit Signal SETC only 6 5 VDC 7 Ground 8 Full...

Страница 30: ...t On Off humidistat Humidity Control can be wall humidity transducer as shown duct humidity transducer or On Off humidistat Knockouts provided in top and bottom panels Install strain relief by others 1509857 2 10V Duct Humidity Transducer 1509858 2 10V Wall Humidity Transducer Insert On Off controls or jumper between 1 and 2 E S X T 1 24 VAC 2 On Off Loop 3 Ground 4 Control Signal 5 Limit Signal S...

Страница 31: ...l ensure accurate representation of the outdoor air temperature Insert Other On Off controls in series 2 On Off Loop 3 Ground 4 Control Signal 5 Limit Signal SETC only 6 5 VDC 7 Ground 8 Full Tank Blow Down 9 Ground 10 Actuator power 11 Actuator power 12 0 10 VDC Out Connect 24 VAC terminal 1 of humidifier to terminal 2 of controllers 1 Ground 2 24 VAC 3 Common 4 Digital Out 5 Fan Relay 6 Fan Rela...

Страница 32: ...ound 10 Actuator power 11 Actuator power 12 0 10 VDC Out SE 50 750 Actuator SE 1050 Actuator SE 1050 low voltage terminal strip Note 1 Wire the CV valve actuator to the low voltage terminal strip Bk R Gr Y Bk 9 Ground 10 Actuator 24 VAC 11 Actuator Ground 12 0 10 VDC Out 2 Use minimum of 18 AWG wire and keep as short as possible SE 50 750 Terminal Strip 9 Ground 3 After installation and powering h...

Страница 33: ......

Страница 34: ...Note Do not reverse polarity Do not connect to pole 1 or 4 Daisy Chain up to 16 Humidifiers Slave 1 Slave X Master Daisy chain pole 2 and 3 of terminalJ2a RS485 of the driver board ...

Страница 35: ......

Страница 36: ......

Страница 37: ... between terminal 1 and 2 on long runs Disconnect Correct voltage amps phase Actuator Opens CV Valve fully at 100 demand Closes fully at 0 Air gap Safety valve if from med or high press boiler Design pressure at 100 demand 1 2 in line min 30 80 PSI Control Wired to terminal 4 On Off in series between terminal 1 and 2 In return duct or location which represents humidified space no drafts not by doo...

Страница 38: ...uttons used to navigate status screens and configure the humidifier correspond to icons on the display Status LEDs Software Drain Button Initiates a software controlled drain On Off Switch Turns humidifier On Off Manual drain switch ...

Страница 39: ...Menu Request xx Idle 0 lb hr 04 30 09 14 25 22 Security loop Closed ...

Страница 40: ...ecurity loop 0 lb hr 14 25 22 Closed Menu CONTROL Man Cap Demand Limit Output 100 55 80 0 lb hr CONTROL Man Cap RH CNT CNT Set Pt RH Limit LIM Set Pt Output Menu 100 55 50 100 70 0 lb hr Menu HUMIDIFIER Model Capacity Multimode REG Mode Software Press In SETC 750 750 lb hr StandAlone Demand XVXX 15 psi ...

Страница 41: ... Valve ON OFF Drain Pump ON OFF Float Level 5 Run Time xxx hr Serv Time xxx hr Serv Due xxx hr Menu SENSOR INPUTS Sec Loop Closed Tank Temp Closed Menu FEATURES LIST Idle Mode Idle Drain FTBD On Off Time Prop On Off BD Rate 25 Drain Cool On Off Smart Float Check On Off Menu FEATURES LIST Idle Mode Idle Drain FTBD On Off Time Prop On Off BD Rate 25 Drain Cool On Off Smart Float Check On Off ...

Страница 42: ...is being overridden by outdoor Output signal is shown on modulating controller proportional to the demand State of On Off humidistat Setpoint RH temperature Option button accesses sensor calibration See troubleshooting Power button turns off the humidiistat if pressed for 2 seconds Increase Decrease Setpoint ...

Страница 43: ...Humidity RH Option button accesses sensor calibration See troubleshooting Adjust calibration while in calibration mode Power button will display if an attempt is made to turn off the transducer ...

Страница 44: ......

Страница 45: ...he CV valve actuator to make steam are as follows The Humidifier will undergo a self test when the power is turned on activating the and other internal components followed by a float test If the above listed prerequisites are fulfilled the humidifier will fill the tank open the CV valve and begin normal operation ...

Страница 46: ......

Страница 47: ... LED On Indicates steam is being produced ON LED Blinking Indicates demand with safety loop open DEMAND LED On Indicates steam is being produced DEMAND LED Blinking Indicates humidifier is in standby waiting for a demand SERVICE LED Flashing Indicates the controller has detected a fault The flash sequence of the LED indicates which fault has been detected FAULT LED On Indicates the controller has ...

Страница 48: ...utor CV Valve Actuator Trap Tank Float Chamber Fill Box Cooling to Float Chamber Dual Fill Valve Boiler Steam CV Valve Vacuum Break Drain Outlet Steam Trap Trap Overflow Condensate Return to Boiler Auxiliary Drain Lower Mixing Box Drain Pump ...

Страница 49: ......

Страница 50: ...SAMe Manifold Insulated copper steam line Support so weight is not on steam outlet Condensate line Trap ...

Страница 51: ...te steam lines Balance steam line length to all blower packs Provide 120 V disconect for blower packs power Wire blwoer pack safety loop terminals in series with humidifier safety loop Condensate to drain Oversize condensate line to combine multiple condensate returns ...

Страница 52: ...vel decrease setting and screen warning or fault message value go up a level Request 100 Idle 04 30 09 Security loop 150 lb hr 14 25 22 Closed Menu Menu Menu Set Menu Set Main Menu Service Level User Defined Settings Control Settings Diagnostics Request 100 Password 0335 Idle 30 lb hr 04 30 09 14 25 22 Enter Code Security loop Closed Confirm with Set Screen Displays Set P 45 45 ESC Set ...

Страница 53: ...hr Tank PreClean Reset Serv Reminder Reset Serv Reminder Set No Yes Menu Set No Yes Menu Set No Yes Menu Menu Menu Set Service Level Service Reminder 500 Service Reminder 500 hr 500 Tank Drain Tank PreClean Reset Error History Reset Serv Reminder Set Reset Error History Reset Error History Menu Yes No Set ...

Страница 54: ...s Idle Mode Idle Time Fill Corr Drain Corr Float Ck Date Time Unit Language Contrast Leak Ck 25 Off Off 100 Idle Drain 72 hr 100 100 23 30 06 27 09 13 22 lb hr English 10 Off Set Menu Set Blowdown Rate 25 BD Rate 25 Menu Set FTBD Time Hour 23 FTBD Time Off Menu Set FTBD Hours 100 100 FTBD Hours 100f Menu Set Full Tank Blowdown Off On FTBD Off ...

Страница 55: ...le Drain Keep Warm Idle Mode Idle Drain Menu Set Idle Time 72 hr 72 hr Idle Time 72 hr Menu Set Fill Correction 100 100 Fill Corr 100 Menu Set Drain Correction 100 Drain Corr 100 Menu Set Float Ck Hour 23 Minute 30 Float Ck 23 30 Menu Set Date Day 27 Month 06 Date 27 06 09 ...

Страница 56: ...Set Time Hour 13 Minute 22 Time 13 22 Menu Set Unit Steam lb hr lb hr kg hr Unit lb hr Menu Set Language English English French Dutch German Language English Menu Set Contrast 10 10 Contrast 10 Menu Set Leak Check Off Off On Leak Ck Off ...

Страница 57: ...n Time Prop Off Manual Cap 100 Mulit Unit Op Range Only present if Multimode set to Master or Slave Modbus Settings Press Base On Supply Press 15 psi Only present if Press Base set to On RH Settings Only present if REG Mode set to RH P or RH PI Analog Digital Menu Set Source Analog Menu Set RegulationMode Demand On Off RH P RH PI REG Mode Demand Menu Set MOD Mode Single CH Single CH MOD Mode Singl...

Страница 58: ... mA 4 20 mA CNT Type 0 10 Menu Set Short Cycle Delay Off Off Short CD Off Menu Set LIM Type 0 10 V 0 5 V 0 10 V 2 10 V 0 16 V 3 2 16 V LIM Type 0 10V Menu Set Short Cycle Delay Time 30 s Short CD Tm 30 s Menu Set Time Proportioning Off Off Time Prop Off Menu Set Manual Capacity 100 100 Manual Cap 100 ...

Страница 59: ...Parity Even On Multi Unit Op Range Menu Set Modbus Settings Parity Even Timeout 300 s Rem Disable On Modbus Settings Menu Set Pressure Based On Off Press Based On Multi Unit Op Range Full Out 20 Zero Out 0 Menu Set ...

Страница 60: ...y present if MOD Mode is set to Dual CH RH Alerts On RH High 75 RH RH Low 33 RH Only present if RH Alerts is set to On RH Settings Menu Set Menu Set Supply Pressure 15 psi 15 psi Supply Press 15 psi Menu Set Control Set Point 40 RH 40 RH CNT Set P 40 Menu Set Control Band 15 RH CNT Band 15 RH Menu Set Control Integral Time 5 min CNT Itime 5 min ...

Страница 61: ...Menu Set Limit Set Point 80 RH LIM Set P 80 Menu Set Limit Band 15 RH LIM Band 15 RH Menu Set Limit Damping 5 s LIM Damp 15 RH Menu Set RH Alerts On On RH Alerts On Menu Set RH High 75 RH RH High 75 Menu Set RH Low 33 RH RH Low 33 RH ...

Страница 62: ...vice History Output Test Remote Test Fault History 04 14 07 21 48 E19A 03 20 09 02 35 E19A Set Menu Set Service History Service History 04 21 07 09 10 03 21 09 10 10 Menu Set Output Test Output Test Inlet Valve Off Menu Set Remote Test Remote Test Steam Relay Off ...

Страница 63: ...Blowdown Adjustment Potentiometer Jumpers J11 to J18 Jumper J10 25 0 50 ...

Страница 64: ......

Страница 65: ......

Страница 66: ......

Страница 67: ...umidifier Maintenance Service timer has expired and humidifier needs maintenance 200 Hours Menu Fault Request 68 Fault LED On HMF Humidifier HMF Humidifier Maintenance Fault 34 lb hr 04 30 09 14 25 22 Security loop Closed Maintenance Service timer 200 hours has passed Maintenance must be performed Humidifier has shut down Menu ...

Страница 68: ......

Страница 69: ...Top Cover Gaskets Tank Door Locknuts Apply anti seize compound to remove Do not crush gasket Max 5 ft lbs torque Top Maintenance Door SE 525 1050 Only Front Cover Front Maintenance Door ...

Страница 70: ... Connection Union Heat Exchanger Gasket Cabinet Cover F T Trap Union F T Trap F T Trap Union Heat Exchanger Heat Exchanger Locknuts Apply anti seize compound to remove Do not crush gasket Max 5 in lb torque ...

Страница 71: ...Caution Do not reverse float chamber hoses To tank To fill valve Squeeze tabs to remove assembly from humidifier ...

Страница 72: ......

Страница 73: ......

Страница 74: ......

Страница 75: ......

Страница 76: ......

Страница 77: ......

Страница 78: ......

Страница 79: ...Clock Fault Controller clock failure Drain Ck Fault The drain pump is activated but water level has not decreased ...

Страница 80: ...Check Fault The fill valve has been active for an extended time without increasing a float level FIF Float Inconsist On startup the unit registers that the float levels do not increase logically from 1 to 5 ...

Страница 81: ...has been active for an extended time without reaching level 1 FTW HMF Maint Fault Warning The Humidifier Maintenance interval and 72 hour window for cleaning has expired HMW The preset service interval time has expired KWF Keep Warm Fault Keep Warm activated but tank temperature has not increased within time allotted ...

Страница 82: ...Fault Warning Float level has dropped multiple times while no steam is being produced LKW LMI Limit Instable Limit signal Is not stable MEM Flash R W Fault Controller Memory failure MTW ModBus Timeout No Modbus signal ...

Страница 83: ...isabled The unit has been remotely disabled through modbus communication or Nortec Online RHW Rh High Warning The measured RH is above the RH High alarm setting RLW Rh Low Warning The measured RH is below the RH Low alarm setting RMW Rh Limit Warning Operation is interrupted until an input higher than 3 is received ...

Страница 84: ...TCF Tank Cold Fault The tank has not become hot with the steam valve activated TCW ...

Страница 85: ......

Страница 86: ......

Страница 87: ......

Страница 88: ......

Страница 89: ......

Страница 90: ...4 3 5 8 9 6 10 19 2 7 18 11 15 1 14 13 12 16 17 ...

Страница 91: ......

Страница 92: ...15 14 16 13 12 3 4 5 5 11 6 10 2 1 9 7 8 17 ...

Страница 93: ......

Страница 94: ...1 10 11 12 13 9 8 14 15 18 17 16 2 7 3 19 5 4 6 ...

Страница 95: ......

Страница 96: ...SETC Electrical SEP Electrical 7 1 1 2 12 7 3 6 9 9 13 5 6 14 4 10 11 15 10 11 8 18 17 16 ...

Страница 97: ......

Страница 98: ......

Страница 99: ......

Страница 100: ...CertificateNo 002419 ...

Страница 101: ......

Страница 102: ......

Страница 103: ......

Страница 104: ......

Страница 105: ......

Страница 106: ... Disconnect Outdoor Cabinet i CabinetDrain _ Drain Pan lectrical Conduits Outdoor Mounting Base With integral drain pan _ Lifting Hook 4 Exhaust Fan Freeze Protection Valve Auxiliary Drain Outlet Freeze Protection Valve Figure2 SETCOutdoorHumidifierComponents ...

Страница 107: ...3 I Introduction ...

Страница 108: ......

Страница 109: ......

Страница 110: ...SETC Outdoor 525 750 SETC Outdoor 100 175 SETC Outdoor 250 375 SETC Outdoor 1050 ...

Страница 111: ......

Страница 112: ......

Страница 113: ... 15 1ft 30 cm 2 in 5 cm min 36 in 91 cm Min top clearance SE525 1050 only 10 in 25 cm Min back clearance SE525 1050 only 30 in 76 cm Min Clearance SE 525 1050 30 in 76 cm Min Side Clearance 30 in only 76 cm Min Front Clearance Location Mounting Pg 9 Plumbing Pg 12 Pressure Steam Pg 14 Pressurized steam supply Condensate return to boiler Tank and auxiliary drain Air gap Water supply 30 80 psig Dedi...

Страница 114: ...ly Mount HumidifierLevel 0 100 Non Condensing As Close as Possible to Steam Distributor 30 in 76 cm 30 in 76 cm 10 in 25 cm Min Min SE 525 1050 only Min Side Clearance 30 in 76 cm SE525 1050 only Min Front Clearance 15 in 37 cm Curb Recommended ...

Страница 115: ...Roof Curb 34 1 in 86 6 cm 15 in 38 cm 0 7 in 17 5 mm 5 in 13 cm 6 in 15 cm 0 75 in 19 mm 3 75 in 9 5 cm Max Pipe Chase Location A Front ...

Страница 116: ...Remove lifting lugs Insert wood block Cabinet Base Pipe Chase Screw to Curb Outside Skirt Inside Skirt Roof Curb Cross section of curb and cabinet base from right side ...

Страница 117: ...freezing can occur Freeze Protection Valve Connection 1 2 in male NPT Air gap required 2 1 2 in to 1 1 4 in copper reducer is ideal Hose line must not touch the bottom of the funnel Always install a water shut offvalve See ProtectingWater Min 1 1 4 in OD drain line Slope down Increase size if combining multiple drains Pipe unions insulation heat trace and water shut off valve not supplied by NORTE...

Страница 118: ...eat trace and insulate Inside Building Remote Relay Board in humidifier Normally Open Valve Error Relay NO COM NO COM NC NO COM NC NO COM Normally Closed Valve 24 VAC From Transformer Ground Water Supply Line To Drain ...

Страница 119: ... IOM manual for size F T Trap Condensate Drain Port see table 3 of SE Indoor IOM manual for size CV Valve As close as possible to humidifier Actuator CV Valve see table 3 Wye Strainer Isolation Valve Boiler steam supply line Max 15 psi Min 5 psi measured at CV Valve Condensate drain line Gravity feed to boiler Use pump if condensate must be lifted ...

Страница 120: ...ate up to cabinet Insulation shown for cut back to show steam connection only Connect to steam outlet with hose cuff 1 ft 30 cm 2 in 5 cm min Run steam line down through roof or across to rooftop air handler ...

Страница 121: ...ection as indicated on the specification label 2 Ensure that adequate power is available to carry full humidifier amp draw as indicated on the specification label 3 Primary power may be routed up through pipe chase and conduit fittings or from roof top source Single Phase Supply Ground L1 Neutral Dedicated circuit breaker or fused disconnect Ground L1 Neutral E I X N T T 4 All wiring to be in acco...

Страница 122: ......

Страница 123: ......

Страница 124: ......

Страница 125: ......

Страница 126: ......

Страница 127: ...ASD BSD 1506162 Distributor End Cap Assembly CSD 1506164 Distributor End Cap Assembly Distributor Core ASD BSD 1506161 Distributor Inlet Assembly CSD 1506163 Distributor Inlet Assembly ...

Страница 128: ...4 3 5 8 9 6 10 19 2 7 18 15 1 11 14 13 12 16 17 ...

Страница 129: ......

Страница 130: ...SETC Outdoor Cabinet and Electrical Parts Figure1 6 SETC P1 00 050 Cabinet and ElectrlcaIParts 25 ISpare Parts ...

Страница 131: ......

Страница 132: ......

Страница 133: ......

Страница 134: ...Certificate No 002419 ...

Результаты поиска

Содержание SE 100

Отзывы:

Похожие инструкции для SE 100

Бренды по названию

Популярные бренды

Nortec SE 100, Инструкция по установке и эксплуатации

Результаты поиска

Содержание SE 100

Отзывы:

Похожие инструкции для SE 100

Бренды по названию

Популярные бренды