Instruction/ maintenance manual of the product RTAA 70-125 TON Trane
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A ugust 2005 RLC-S VD03A -EN © American Standard Inc. 2005 Model RT AA 70-1 25 T on RTWA 70-1 25 T on RTU A 7 0-125 T on Diagnostic T r oubleshooting Repair Ser ies R ® 70-125 T on Air -Cooled and W.
2 RLC-SVD03A-EN Import ant - Read This First! This manual is int ended f or exper ienced service personnel f amiliar with the proper use of electr ical diagnostic instruments and all personal saf ety pr ocedur es when wo r king on liv e electr ical cir cuits.
RLC-SVD03A-EN 3 Contents General Informati on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Service Philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 System Description .
4 RLC-SVD03A-EN General Inf ormation The Unit Control Modules (UCMs) described in this trouble shooting guide provide a microprocessor ba sed refrig eration control system, intended for use with T rane 70-1 25 ton helical roto r c hillers.
RLC-SVD03A-EN 5 General Inf ormation S ystem Descr iption The CPM is the master module and coordin ates operation of the entire system. One is used per c hiller . T he MCSP is a compressor protection module with one being u sed for eac h of the compressors in the c hiller .
6 RLC-SVD03A-EN General Inf ormation High Pressure Cutout S witc h Lo w Pressure Cuto ut Switc h V ariable Speed Fan Drive Motor T emperat ure T hermostats Slide V alve L oad/Unload Solenoids Step Load Solenoid V alve Chiller Module (CPM) IU 1 The CPM module perf orms mac hine (c h iller) lev el control and protection functions.
RLC-SVD03A-EN 7 General Inf ormation Real t ime dat a fo r temperature s, diagno stics and control algorithms etc. are made a vailable to t he CPM and the other modules f or display and f or input to higher le vel fun ctions. See Electronic Expansion V alv e Module (EXV) (1U3) on page 58 f or details.
8 RLC-SVD03A-EN Interpr ocessor Communications The respective modules communicate with eac h other v ia an InterProcessor Communication link (IPC). The IPC allo ws the modules to work in a coordi- nated manner with the CPM directing ov erall c hiller operation while eac h module handles specific subf unctions.
RLC-SVD03A-EN 9 Interpr ocessor Communication from the Options Modu le. When some problem ex ists with the IPC link or a module fa ils, it is not uncommon for more than on e of these IPC diagnostics to be displa yed . Note that only those diagnostics that ar e indicated to be active currently e xist.
10 RLC-SVD03A-EN Interpr ocessor Communication Figure 1 IPC Link Order For 70-125 T on RT AA * #,$ 5 * -3#0" .
RLC-SVD03A-EN 11 Interpr ocessor Communication . 3. Loss of po wer t o a module: Generally a pow er loss to a particular module will only af f ect communica- tions with that mo dule. The module can usu ally be identified by analy sis of the IPC diag nostics.
12 RLC-SVD03A-EN Interpr ocessor Communication 5. Improper connections to terminal J2: Jac k J2, present o n all modules ex cept CLD , should hav e no connections. This inpu t is for manuf acturing te st purposes only and any con nections, shorts, etc.
RLC-SVD03A-EN 13 Interpr ocessor Communication 3. Determine whic h modules are still t alkin g . Wiring up to these is likely to be OK. 4. T r y disconnecting th e link or jumping out mo dules in the link at v arious places (use Figu re 1 ). Reset the diagnostics an d note wh ic h diag nostics reappear .
14 RLC-SVD03A-EN Interpr ocessor Communication The CPM has detected lo ss of comm unications with MCSP A, MCSP B , and EXV . Suspect an open early in the I PC link bet w een the CPM and MCSP B . The re are a large number of possible combinations of di agnostics.
RLC-SVD03A-EN 15 T e mperature Sensor Chec kout With the ex ception of the thermo stats located in the motor windings of the screw compressors, all the temperat ure sensors used on the UCMs are negativ e temperat ure coef ficient (NTC) thermistors.
16 RLC-SVD03A-EN T e mperature Sensor Chec kout 4. Again measure the temperat ure at the sensor with an accurate thermom- eter; record the te mperature reading obser ved. 5. Remo ve the sensor leads from the terminal strip or unplug the respective MT A.
RLC-SVD03A-EN 17 T e mperature Sensor Chec kout . 1. Overall accu racy for any of the sensors is at l east + 2 F over the ra nge shown. Accur acy of matched sens ors is + 1 F over sp e cific ra nges.
18 RLC-SVD03A-EN T e mperature Sensor Chec kout 1. Overall accu racy for the se nsor is at least + 2 F over the range shown. 2. As yo u compare a thermi stor resistance (or input voltag e) reading wit.
RLC-SVD03A-EN 19 Compressor Operation This f eature is calle d the Auto L ead/Lag and can be fou nd in the Ser vice Set tings Group, under th e “Balance d CPRSR Starts and Hours” menu. When this function is disable d, the UCM alwa ys starts comp ressor “ A ” first.
20 RLC-SVD03A-EN Compressor Star t/Stop T o st art a compressor af ter either a “nor mal' shutdown, a Diag nostic reset, or pow er -on-reset, the follo wing sequence will occur: 1 . On a call for a compressor , the Restart Inhibit Time r will time out, if any time remains.
RLC-SVD03A-EN 21 V ariable Speed In v er ter/Condenser F an Contr ol When Fa n Control and V ariable Speed Fan (VS F) are set to Enable in the Mac hine Configuration Me nu, the UCM will control both the v ariable speed fa n and the remaining constant speed f ans per the VSF Control Algor ithm.
22 RLC-SVD03A-EN V ariable Speed In v er ter/ Condenser F an Contr ol speed will also cause const ant speed f ans to s tage On and Off when the inv erter is co mmanded to full spee d and minimum speed respectively . The stage On (or Off) of a constant speed fan will occur if the in verter speed command is at max (or min.
RLC-SVD03A-EN 23 Current T ransf ormer Eac h compressor motor has all three of its line currents monito red by tor roid (doughnut) current transf ormers. Wh ile the MCSP utilizes all three of the signals, it only display s the maximum phase at an y given time .
24 RLC-SVD03A-EN Current T ransf ormer will be display ed. If this protection is disabled, a 30% phase unbala nce will still be in ef fect with the diag nostic code Sev ere Phase Imbala nce being displayed. 6. Current Limit. The MCSP wil l begin to unload it s compressor as the %RLA ex ceeds 1 20%.
RLC-SVD03A-EN 25 Current T ransf ormer W ARNING Hazardous V oltage w/Capacitor s! Disconnect all electr ic power , including r emote disconnects befor e servicing. Follo w pr oper lock out/tagout pr ocedures t o ensur e the po wer cannot be inadver ten tly energiz ed.
26 RLC-SVD03A-EN Current T ransf ormer essar y to remove a cap o ver the top of the connector to gain access to the connector conductor s.) 6. Ref er to Ta b l e 7 whic h lists the normal resist ance range f or eac h exten- sion of cur rent transf ormer .
RLC-SVD03A-EN 27 Current T ransf ormer with all phase currents to the compressors verified t o be within th eir nor- mal range, then the problem is either with the CT selection, MCSP Com- pressor O verload Dip S witc h Set ting , or the MCSP's current input, analog to digital (A/D), or dip switc h input circuitr y .
28 RLC-SVD03A-EN Current T ransf ormer T able 5 Compressor Over load DIP Switch Settings Compr essor To n s Vo l t s / H z RLA Pr imary T ur ns Through Cur rent T ransf ormer Cur rent T ransf or mer E.
RLC-SVD03A-EN 29 Current T ransf ormer T able 6 T r ip Times Vs. % Cur r ent MO T OR CURRENT (% RA TED RLA) MINIMUM TRIP TIME (SE C) NOMINAL MAXIMUM 1 27 .7 or below No trip No T rip No T rip 1 32.0 27 .2 No T rip No T rip 1 32.1 27 .2 30.08 No T rip 1 40.
30 RLC-SVD03A-EN Current T ransf ormer T able 8 Compressor Phase Cur rent vs. A C Input V oltage at MCSP ACTU AL COMPRESSOR PHASE AMPS THRU CT TERMINAL VO LT A G E (V RMS) % OF CT RA TING EXT -0 1 EXT -02 EXT -03 EXT -04 EXT -05 EXT -09 EXT -1 0 00 0 0 0 0 0 0 .
RLC-SVD03A-EN 31 Current T ransf ormer T able 9 Over load Di p Switch Set ting vs. Internal Sof twar e Gain CPRSR RA TED RLA AS A % OF CT RA TING OV E R LOA D D P SWITCH SET TING DECIMAL SETTING SOFTW ARE GAIN 66 00000 00 1 .500000 67 00 00 1 0 1 1 .483870 68 00 0 1 0 02 1 .
32 RLC-SVD03A-EN Under -Ov er V oltage T ransf ormer The hardware required for the Under/Over v olt age sensing func tion of the UCM is st andard on the 70-1 25 T on RT AA c hiller . This f eat ure must be Enabled in the Ser vice Set tings Menu f or it to be active.
RLC-SVD03A-EN 33 Under -Ov er V oltage T ransf ormer replacing the CPM, double c hec k the Under -Ov er V oltage F unction's Nominal Line V oltage Set up in the Ser vice Sett ings Group.
RLC-SVD03A-EN 34 Compressor Capacity The 35 to 60 ton helical rotar y scre w compressors are loaded and unloaded by means of an intern al slide v alve an d a f emale unloader valve. In simple terms, these v alves can regulat e the amount of “bite ” of the compressor rotors as they t urn at r elatively const ant spee ds.
RLC-SVD03A-EN 35 Compressor Capacity Check out Procedur e for MCSP Load/Unload Outputs W ARNING Liv e Electrical Components! Dur i ng installation, t esting, servicing and tr oubleshooting of this pr oduct, it may be necessary t o w or k with live electr ical components.
36 RLC-SVD03A-EN Compressor Capacity prev ent a compressor from loading even if the c hilled water setpoint is not satisfied. R efe r to the RT AA-IOM-4 for discussion on condenser , evap orator , and current limit ing functions and setpoints.
RLC-SVD03A-EN 37 Compressor Capacity NO TE: Ena bling the “Compr essor T e st” only af f ect s whic h compressor will be cycled on ne xt and is not an ov er ride mode.
38 RLC-SVD03A-EN Compressor Capacity Unload NO TE: The f ollowing assume s that the compressor's slide valv e is already at some loaded position and %RLA is higher than the minimum noted in step 1. 1 . Manually close the Unload toggle swit c h to continuo usly energize the Unload Solenoid V alve.
RLC-SVD03A-EN 39 Compressor Capacity pressure, then the Slide V alve is b ound. 5. If cylinder ca vity pressure does not decrease or is at suction pressure before the Unload toggle swit c h was closed, the prob lem lies with either the solenoid coil o r valv e.
40 RLC-SVD03A-EN Compressor Capacity W ARNING Liv e Electrical Components! Dur i ng installation, t esting, servicing and tr oubleshooting of this pr oduct, it may be necessary t o w or k with live electr ical components.
RLC-SVD03A-EN 41 Module P o w er and Miscellaneous I/O This section will detail the normal volt age levels present on eac h of the modules inpu ts and outpu ts under various conditio ns or st ates. T ypica l operation of the I/O will be discussed in terms of c hiller operation.
42 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Clear Languag e Display (C LD) 1U6 Ke ypad Overview Local oper ator interface with th e system is accomplished using the 1 6 ke ys on the front of the Clear Langua ge Display panel. The readout scree n is a two line, 40 c haracter liquid cr ystal display with a bac klight.
RLC-SVD03A-EN 43 Module P o w er and Miscellaneous I/O Select Report Gr oup This gr oup of four k ey s allows the op erator to select and vie w the f ollowing reports: - Custom R eport - Chiller Report - Refrigerant Report - Compressor Report The Custom Report is the only report of the four that is defined by the operator .
44 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O When an y of the four rep ort ke ys are presse d, the first readout on th e display will be the header .
RLC-SVD03A-EN 45 Module P o w er and Miscellaneous I/O Press Ne xt to move do wn through the Chiller R eport. As shown in the figures, the flo wc hart e xplains the conditions that the UCM loo ks at to determine whic h readout is to be displa yed ne xt.
46 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O When updating is successfully completed, the system will default to the first displa y af ter the Chiller Report header: MODE: OPERA TING MODE] REQUESTED SE TPOINT SOURCE: [SETPT SO URCE] and the bac klight will be activated.
RLC-SVD03A-EN 47 Module P o w er and Miscellaneous I/O Te s t P o i n t s The re are t wo test points associated with the CPM module. T hey ar e easily read with a DC vo ltmeter by pr obing the PC board solder pads f ound in the upper lef t hand corner of the module.
48 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O I/O ter minal s F or the c hec kout of the I/O , ref er to the bloc k diagram of the module in Figure 10 and the Chiller Wiring Diagrams for both high and low voltage circuits. All vo lt ages are measured dif f erentially between terminal pairs sp ecified unless other wise indicate d.
RLC-SVD03A-EN 49 Module P o w er and Miscellaneous I/O T able 16 CPM (Chiller) Nomin al T ermin al Input and Output (1U1) Te r m i n a l Designation Descr iption of Circuit Nor mal T erminal V oltages for V arious Conditions J1 -4 to 3 to CLD J1 -2 to 1 to 1U5 IPC Communications 1 9.
50 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Options Module (CSR) (1U2) W ARNING Liv e Electrical Components! Dur i ng installation, t esting, servicing and tr oubleshooting of this pr oduct, it may be necessary t o w or k with live electr ical components.
RLC-SVD03A-EN 51 Module P o w er and Miscellaneous I/O 2. Has its negativ e terminal tied to c hassis ground. If the intended source does not meet the ab ov e requirement, an iso lation module must be used The 4-20mA/2-1 0VDC input s may be tested in the following wa ys: 1 .
52 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Setpoint Pr iority There are many w ay s in whic h the Ch illed W ater and Curren t Limit setpoints can be adjusted or reset when the Options Module is present in the Chiller control system.
RLC-SVD03A-EN 53 Module P o w er and Miscellaneous I/O “TRACER” implies Trane Integrated Comfort System remote device (ICS) using the di gital communicatio n link. “EXTERNAL” implies generic building automati on system or process controller interfac e using a 4-20ma loop or a 2-10 VDC analog signal.
54 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O “TRACER” implies Trane Integrated Comfort System remote device (ICS) using the di gital communication link. “EXTERNAL” implies generic building automation system or process controller in terface using a 420ma loop or a 2-10 VDC a nalog signal.
RLC-SVD03A-EN 55 Module P o w er and Miscellaneous I/O ICS Communications ICS (T racer) communication is handled the same as on previo us products using the T rane proprietar y Comm3 st andard 1 20 0 baud isolated serial communication link. T he f ollowing are some thing s to c hec k when experi- encing loss of ICS communications: 1 .
56 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O T able 19 CSR Normal T er minal V olt ages f or Options Module 1U2 Te r m i n a l Designation Descr iption of Cir cuit Nor mal T er minal V oltages for V ar ious Conditions J1 -4 to 3 or J1 -2 to 1 IPC Communications 1 9.
RLC-SVD03A-EN 57 Module P o w er and Miscellaneous I/O ° TP1 +5V ° TP2 + 6V J6-1 — 1 1 5V A C HO T J6-2 — 1 1 5V A C HO T ° TP2 + 1 2V J6-3 — KEY (N/C) J6-4 — NEU TRAL IPC (+) — J1 -4 J6-5 — NEU TRAL IPC (-) — J1 -3 IPC (+) — J1 -2 IPC (-) — J1 -1 MANUF .
58 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Electr onic Expansion V alve Module (EXV) (1U3) W ARNING Liv e Electrical Components! Dur i ng installation, t esting, servicing and tr oubleshooting of this pr oduct, it may be necessary t o w or k with live electr ical components.
RLC-SVD03A-EN 59 Module P o w er and Miscellaneous I/O A “FLA G” stop is located at either end of the threaded portion of t he motor shaf t. The stops inter f ere with the milled flag on the driv e coupling, restricting rotation of the motor shaf t and producing a clic king sound when the v alve is driven fully OPEN or CLOSED .
60 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Electr onic Expansion V alv e Location The valve sho uld be inst alled with the motor in a v ertical position, or no greater than 45° from vertical, as shown in Figure 1 6 . This will prev ent oil logging and the possibil it y of contamination reac hing the motor cavity .
RLC-SVD03A-EN 61 Module P o w er and Miscellaneous I/O Te s t P o i n t s There is only on e test point associated with the EXV module. It is easily read with a DC voltmete r by probing the PC board sold er pad found in the upp er lef t hand corner of the module.
62 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O diagnostic sugg ests that there is a problem with the v alv e or the valv e wiring. T o confirm this, it is necessar y to continue the procedure. T he Electrical Integrit y test will be completed in about 2 seconds.
RLC-SVD03A-EN 63 Module P o w er and Miscellaneous I/O 3. Chec k the resist ance from eac h of the three phase pins (J4-3, J4-2, and J4-1) to the boar d edge GND , with the conne ctor unplugge d. This resis- tance should be between 1 00K and 200K ohms.
64 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O used, it is important to direct the flame aw ay f rom the va lve body . See Figure 17 . A wet cloth should be wrapped around the body during sold ering to provide e xtra protection.
RLC-SVD03A-EN 65 Module P o w er and Miscellaneous I/O 2. Disconnect all the line v oltage to the pow er supply of this unit. 3. Ref er to the e xploded view in Figure 1 8 while pe rforming the remaining instructions. CA UTION P rev ent Injur y! Ref er to Figur e 18 .
66 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O to the v alve body until t he sealing surfaces mak e contact. Tighten the actu ator approximately 1/8 t urn to seal the knif e edge joint. 1 2. The motor cap quad-ring ma y be replaced by removing the f err ule motor cap nut.
RLC-SVD03A-EN 67 Module P o w er and Miscellaneous I/O SEHI Electr onic Expansion V alve Servicing The procedures liste d below are to. be follow ed for proper d isassembly , inspection, cleaning and reassembly to the valv e. The v alve does not ne ed to be remov ed from th e refrigerant pipin g before ser vicing .
68 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Figur e 19 SEHI Electr onic Expansion V alve Exploded V iew -OTOR!DAPT OR !SSEMBLY 0ISTON!SSEMBLY "ODY!SSEMBLY 3IGHTGLASS.
RLC-SVD03A-EN 69 Module P o w er and Miscellaneous I/O SEO V alve Module ° TP1 +5V J 6-1 — 1 1 5V AC H OT J6-2 — 1 1 5V A C HO T J6-3 — KEY (N/C) J6-4 — NEU TRAL IPC (+) — J1 -4 J6-5 — NEU TRAL IPC (-) — J1 -3 IPC (+) — J1 -2 IPC (-) — J1 -1 MANUF .
70 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O I/0 ter minal s F or the c hec kout of the I/O , ref er to the bloc k diagram of the EXV module in T able 21 and the Chiller W iring Diagrams for both high and lo w voltage circuits.
RLC-SVD03A-EN 71 Module P o w er and Miscellaneous I/O specified, unless ot her wise indicated. Th e first te rminal in the pair is the positive (or hot) terminal. V olt ages giv en are nominals and ma y vary by ±5%. Unregulated V oltages (unreg) or 1 1 5 V A C voltages may v ar y by ±1 5%.
72 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Compr essor Module (MCSP) (1U4 AND 1U5) W ARNING Liv e Electrical Components! Dur i ng installation, t esting, servicing and tr oubleshooting of this pr oduct, it may be necessary t o w or k with live electr ical components.
RLC-SVD03A-EN 73 Module P o w er and Miscellaneous I/O Binary Inputs The binar y inputs shown in T able 22 all use the same basic circuit . A pullup resistor to the 1 2V pow er supply is connected to the higher numbered input pin. T he low er numbered pin is connected to g round.
74 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O the currents are higher than actual and will sho w up as a n error in the %RLA displa yed b y the CPM.
RLC-SVD03A-EN 75 Module P o w er and Miscellaneous I/O I/O T er minals F or the c hec kout of the I/O, ref er to the block diagram of the MCSP module in Figure 22 and the Chiller Wiring Diagrams for both high and low voltage circuits. All volt ages are measur ed dif f erenti ally between term inal pairs specified un less other wise indicat ed.
76 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O J7 -8,9 Step Load Solenoid N ormally open contact, clos es to energize the Step L oad Solenoid V a lve. J7 -1, E7 Slide V alve Open (Load Solenoid) Output T riac Output, Ref er to Chec kout P rocedure for MCSP Load/Unload Outputs.
RLC-SVD03A-EN 77 Module P o w er and Miscellaneous I/O ° TP1 +5V ° TP2 +1 2V J6-1 — 1 1 5V A C HO T J6-2 — 1 1 5V A C HO T J6-3 — KEY (N/C) J6-4 — NEUTRAL IPC (+) — J1 -4 J6-5 — NEUTRAL IPC (-) — J1 -3 IPC (+) — J1 -2 E3 — COMPRESSOR MO T OR IPC (-) — J1 -1 E4 — WINDI NG THERMOST .
78 RLC-SVD03A-EN Module P o w er and Miscellaneous I/O Inter pr ocessor Communication Bridg e Module (IPCB) (1U7) The IPCB provides an extension of the IPC link to th e Remote Clear Lang uage Display . See Figure 23 It prev ents “crashes” of the IPC and UCM if t he link to the RC LD is shorted or misapplied.
RLC-SVD03A-EN 79 Module P o w er and Miscellaneous I/O LonT alk® Communications Inte rf ace - Chillers Module (LCI-C) (1U8) The T racer LCI -C interf ace acts as a tr anslator bet w een T rane's IPC (Inter - Processor Communication ) and Ec he lon' s LonT alk® communications protocol (ANSI/EIA/CEA 709.
80 RLC-SVD03A-EN V ariable Speed F an System The purpose of this troubleshooting guid e is to help tec hnicians determine if the v ariable speed f an inv erter , the compressor module, the vari able speed fa n inv erter contactor , the f an motor or the inte rconnecting wiring is f aulty .
RLC-SVD03A-EN 81 V ariable Speed F an System Bus Ov er voltage Fau lt 2 Motor Overload F ault 3 Lo w Bus V oltage Fault 4 PWM Gene rator Fault 5 Log i c Fa u l t 6 Stalled Motor F ault 7 F ault Descr iptions Bus Over curr ent F ault: DC Bus Current e xce eds the driv e rated peak current.
82 RLC-SVD03A-EN V ariable Speed F an System T roubleshooting Pr ocedur e W ARNING Liv e Electrical Components! Dur i ng installation, t esting, servicing and tr oubleshooting of this pr oduct, it may be necessary t o w or k with live electr ical components.
RLC-SVD03A-EN 83 V ariable Speed F an System .6 VDC. If there is n o voltage at either of th ese t wo test points, c hec k the incoming 1 1 5 V A C bet w een pins J6-1 (hot) and J6-5 (neutral) and c hec k fuse F1, mo unted on th e upper righ t-hand corner o f the circuit board.
84 RLC-SVD03A-EN V ariable Speed F an System on at both ends while measuring this voltage. If the reading is between 1 1 .5 and 1 2.5 VDC, two problems m ay e x ist: • The in verter indicates that it has a fault b y opening a semiconductor switc h within the inverter .
RLC-SVD03A-EN 85 Other S er vice F eatures Service Pumpdo wn The UCM pro vides for a "one time" Ser vice Pumpdo wn mode, in whic h a ser vice-tec hnician can direct a particul ar compressor to start and run f or one minute, to accomplish pumpdown of the low side of the r efrigeration system (ev aporator and EXV).
86 RLC-SVD03A-EN Other S er vice F eatures W ARNING Hazar dous V o ltag e w/Capacitors! Disconnect all electr ic power , including r emote disconnects befor e servicing. Follo w pr oper lock out/tagout pr ocedures t o ensur e the po wer cannot be inadver ten tly energiz ed.
RLC-SVD03A-EN 87 Other S er vice F eatures tioned (if not already controlling). Most of ten the st age-on will be ac com- panied b y a controlled stage-of f of an already r unning compressor . Since normal operation is in ef f ect, a constant load or setpoint c hange may be required to k eep the compressor fr om st aging of f later .
T rane ha s a policy of continuous product d ata and p roduct improv ement and reser ves the right to c han ge design and specifications without notice. Only qualified tec h nicians should perform the inst allation and ser vi cing of equipment referred to in this bulletin.
An important point after buying a device Trane RTAA 70-125 TON (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Trane RTAA 70-125 TON yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Trane RTAA 70-125 TON - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Trane RTAA 70-125 TON you will learn all the available features of the product, as well as information on its operation. The information that you get Trane RTAA 70-125 TON will certainly help you make a decision on the purchase.
If you already are a holder of Trane RTAA 70-125 TON, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Trane RTAA 70-125 TON.
However, one of the most important roles played by the user manual is to help in solving problems with Trane RTAA 70-125 TON. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Trane RTAA 70-125 TON along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
