Carrier 48FK manual

Controls Operation, and T roubleshooting CONTENTS Page SAFETY CONSIDERA TIONS .....................2 GENERAL ................................... 2-13 Rooftop Information ............................2 V A V Control System ...........................2 Processor Board ..............................2 • P1 — SUPPL Y -AIR SET POINT • P2 — ECONOMI[...]

CONTENTS (cont) Page • CODES 59 AND 60: LOW -PRESSURE SWITCH • CODES 63 AND 64: OIL PRESSURE SWITCH • CODE 70: ILLEGAL UNIT CONFIGURA TION • CODES 71 TO 76: THERMISTOR/RESISTOR F AILURE • CODE 81: RESET THERMISTOR OR POTENTIOMETER F AILURE • CODE 82: LEA VING-AIR TEMPERA TURE SET POINT POTENTIOMETER F AILURE • CODE 83: ECONOMIZER FEED[...]

Several temperature inputs are connected to the proces- sor . There are either 4 or 5 thermistors (depending on the field-installed accessories) which input temperature data into the processor through pin terminal connector J1. See T able 1 and Fig. 2. Several status switches are also monitored. These switches are connected to the processor at pin[...]

T able 2 — Pin T erminal Connector J2 Status Switch Inputs CONNECTOR J2 TERMINAL NO. ST A TUS SWITCH UNIT SIZE 034-104 1,2 Oil Pressure, Circuit 2 Jumpered 3,4 Oil Pressure, Circuit 1 Jumpered 7,8 Loss Of Charge, Circuit 2 LPS2 9,10 Loss of Charge, Circuit 1 LPS1 13,14 Economizer Changeover EC 15,20 Compressor Fault Signal CR2 15,24 Compressor Fa[...]

The potentiometer locations and functions are as follows: P1 — SUPPL Y -AIR SET POINT — This potentiometer is located on the display board. The supply-air set point is the cooling mode control temperature which the V A V control system will attempt to maintain at Thermistor T1 by con- trol of economizer position and/or cycling unloaders and com[...]

T able 3 — Output Pin and T erminal Assignments OUTPUT PIN- TERMINAL NAME RA TING DEVICE J6-1 Stage 1 Compressor Relay (K1)* 24 vac CR1 J6-2 Stage 2 Compressor Relay (K2)* U2** J6-3 Stage 3 Compressor Relay (K3)* U1 J6-4 Stage 4 Compressor Relay (K4)† Not Used J6-5 Stage 5 Compressor Relay (K5)† CR2 J6-6 Stage 6 Compressor Relay (K6)† Not U[...]

Compressor Operation CONTROL RELA Y (CR) — This relay provides informa- tion to the processor about compressor operation (one con- trol relay per compressor). The relay controls and protects the compressor and also controls the crankcase heater . A control signal to check the safety statuses and to start the compressor is sent from the relay boar[...]

GAS SECTION HORIZONT AL SUPPL Y SECTION (48FK,JK ONL Y) (50FY ,JY ONL Y) AND EXTENDED PLENUM SECTION (50FKX,FKY ,JKX,JKY) Fig. 7 — Thermistor T1 Location, 48FK,JK, 50FY ,JY and 50FKX,FKY ,JKX,JKY 034-048 Units F AN DISCHARGE/ELECTRIC HEA T SECTION Fig. 8 — Thermistor T1 Location, 50FK,JK034-048 Units 8[...]

GAS SECTION HORIZONT AL DISCHARGE SECTION (50FY ,JY) (48FK,JK) AND EXTENDED PLENUM SECTION (50FKX,FKY ,JKX,JKY) Fig. 9 — Thermistor T1 Location, 48FK,JK, 50JY and 50JKX,JKY 054-074 Units and 50FKX,FKY and 50FY054-104 Units F AN DISCHARGE/ELECTRIC HEA T SECTION Fig. 10 — Thermistor T1 Location, 50FK,JK054-074 Units 9[...]

Economizer — Economizer control is used to control the outside and return air dampers of the unit, to satisfy space cooling demand using all outside air (when permitted), and to satisfy cooling in conjunction with compressor operation (when conditions permit). During Occupied periods without cooling demand, the outside-air dampers will be at the [...]

054 UNITS 064, 074, 078 UNITS 088, 104 UNITS Fig. 14 — Thermistor T3 and T4 Locations, Size 054-104 Units 11[...]

V ariable Frequency Drive (VFD) — The optional VFD is used to modulate supply fan airflow to maintain duct static pressure on V A V applications. The VFD is located in the supply fan section (see Fig. 18 and 19), and can be ac- cessed by opening the fan section access door . The unit is supplied with a pressure transducer capable of measuring fr[...]

capacity stages to maintain user-established supply-air set point temperature. When V A V units are also equipped with optional supply duct pressure controls (either inlet guide vanes [IGV] or variable frequency drive package), the unit also senses an increase in duct static pressure and responds by closing IGV dampers or slowing fan wheel speed to[...]

Fig. 20 — Unit Control Box Arrangement, Sizes 034-048 14[...]

Fig. 21 — Unit Control Box Arrangement, Sizes 054-078 15[...]

Fig. 22 — Unit Control Box Arrangement, Sizes 088 and 104 16[...]

EXAMPLE: T10 desired set point is 70 F . T10 R from T able 4 for 70 F is 5929 ohms. P7 R = 13,084 – 5929 P7 R = 7155 ohms Using an ohmmeter , set the P7 potentiometer to 7155 ohms to achieve a reset initiation set point of 70 F . Potentiometer P3 — Reset limit set point (maximum tem- perature value for modified supply air set point). Maximum o[...]

Demand Limit — The demand limit function provides a means to limit the cooling capacity of the V A V unit using an external discrete switch function. When enabled by the closure of the external switch, the control will limit the avail- able compressor staging capacity according to user set points established at demand limit potentiometer(s). The [...]

Connect the potentiometer end terminals to terminals 8 and 9 on control terminal block TB3 (sizes 034-048) or TB4 (sizes 054-104) (see Fig 27). Connect the switch terminals to the potentiometer wiper arm terminal and to terminal 10 on TB3 or TB4. T o enable demand limit function, change DIP switch 5 to position ON. (Disconnect control power before [...]

OCCUPIED/UNOCCUPIED — The unit control system will initiate normal occupied mode functions (including Morn- ing W arm-up, Economizer Minimum Position, and Cooling Cycle) whenever a contact closure is made that emulates the normal timeclock contacts. See Fig. 23. (‘ ‘Occupied/Unoccupied Switch’ ’). The contact closure from the BMS must be [...]

EXTERNAL ALARM SIGNAL — The unit controls pro- vide an external alarm status signal via a 1 15-vac output sig- nal at the relay board J5, available at TB2-4 and TB2-5 (common). This signal can be forwarded to the BMS by add- ing a signal relay at the alarm output, placing its coil across terminals TB2-4 and TB2-5 and using its contacts to control[...]

INST ALLA TION — T o enable one or more of the possible smoke control modes available with these units, determine the switches required for the desired mode(s) from T able 6, field-supply and install the appropriate switches and field wire per Fig. 32. Switch functions are shown in T able 7. T able 5 — Smoke Control Modes FUNCTION MODE Fire S[...]

T able 7 — Switch Functions SWITCH NUMBER CONFIGURA TION VOL T AGE FUNCTION SW-1 N.C. 1 15 Deenergize 1 15-v (OFC, Comp, IFC, Electric Heaters) SW-2 N.C. 1 15 Deenergize TRAN7 (Process Board) SW-3 N.O. 24 Energize EOR (Open Economizer Outside Air Dampers) SW-4 N.O. 1 15 Energize IFC and CR-3 (IGV/VFD) SW-5 N.C. 1 15 Isolate IFC and PEC for Separa[...]

VIO NC NO C WHT REMOVED FROM C-DPS SW-8 SW-7 ALL UNITS DPS GRA REMOVE JUMPER 034-048 UNITS 5 6 TB2 TB2 SW-1 1 2 TB2 TB2 SW-2 REMOVE JUMPER 8 9 TB2 TB2 SW-5 REMOVE JUMPER TB3 SW-3 TB3 1 5 TB2 TB2 5 9 SW-4 TB2 SW-6 TB2 5 8 TB3 TB3 SW-9A 3 4 TB4 TB4 SW-9A 3 4 TB4 REMOVE JUMPER 054-104 UNITS 13 14 TB2 TB2 SW-1 7 8 TB2 TB2 SW-2 REMOVE JUMPER TB4 SW-3 TB[...]

MODULA TING POWER EXHAUST — The tubing for the building pressure control (achieved via the Modulating Power Exhaust option) should sample building pressure in the area near the entrance lobby (or other appropriate and sensitive location) so that location is controlled as closely to design pressures as possible. A dif ferential pressure switch (DP[...]

T able 9 — Potentiometer Inputs and Ranges POTENTIOMETER DESCRIPTION LOCA TION CONTROL V ALID RANGE DEF AUL T V ALUE P1 Supply Air Set Point Display Board 45 to 70 F 4 5Fi f- 2 2F<P 1<4 5F 7 0Fi fP 1>7 0FO RI FP 1<- 2 2F P2* Economizer Position Economizer Motor 0 to 100% None (0 if P2 is bad) P3 Reset Limit Accessory Board 0 to 80 F N[...]

DIP SWITCH NO. 1 — Supply Air Set Point (SASP) Reset T ype. Factory setting is OFF . Do not change. DIP SWITCH NO. 2 — SASP Reset Enabled. Factory set- ting is OFF (no SASP reset enabled). If SASP reset has been installed, enable it by changing switch position to ON. DIP SWITCH NO. 3 — Economizer option. If economizer option has been installe[...]

Supply Fan Control with IGV Option — The inlet guide vane option will modulate the supply fan airflow in order to maintain the static pressure in the supply duct. The set point for duct static pressure is established at the dif fer- ential pressure switch for the IGV control. SIZE 034-048 UNITS — The inlet guide vane dif ferential pressure swi[...]

DETERMINE VFD SET POINT — The unit of measure for the Duct Pressure set point at the VFD is output frequency (Hz), representing the desired DP set point (DPSP) in inches of water gage (in. wg). T o convert desired DPSP into the VFD set point, refer to T able 13. Locate the pressure value in the table closest to the desired DPSP for this installat[...]

T able 13 — VFD Set Point (Frequency Command) for Duct Pressure PRESSURE (in. wg) VFD SET POINT (Hz) CONTROL SIGNAL (mA) PRESSURE (in. wg) VFD SET POINT (Hz) CONTROL SIGNAL (mA) 0.00 0 4.0 2.00 24 10.4 0.25 3 4.8 2.25 27 1 1.2 0.50 6 5.6 2.50 30 12.0 0.75 9 6.4 2.75 33 12.8 1.00 12 7.2 3.00 36 13.6 1.25 15 8.0 3.25 39 14.4 1.50 18 8.8 3.50 42 15.[...]

ST ART UNIT T o start unit: 1. Close the unit-mounted ON/OFF switch (located in the main control box). 2. Close the field-supplied and -installed timeclock (or con- trol) switch (contacts located at T erminals 1 and 2 (TB3 for 034-048, TB4 for 054-104). IMPOR T ANT : The field-supplied and installed switch (or timeclock) MUST BE CLOSED to put uni[...]

T able 15 — Quick T est, Unit Configuration and Switch Check QUICK TEST STEP NO. NORMAL DISPLA Y DESCRIPTION CONTROL SWITCH 1. 01 T ype Unit — Air-Cooled V A V Configuration Header 2. 2 No. of Compressors Configuration Header 3. 2 1 No. of Unloaders (034,038,048-088) (044, 104) DIP Switch No. 6 and 7 4. 60 60-Hertz Power Configuration Heade[...]

T able 16 — Quick T est, Thermistor and Potentiometer Check QUICK TEST STEP NO. NORMAL DISPLA Y DESCRIPTION THERMISTOR OR POTENTIOMETER* 1.4. 1 1 — Thermistor OK 0 — Thermistor Faulty Supply Air Thermistor (T1) 1.5. 1 1 — Thermistor OK 0 — Thermistor Faulty Return Air Thermistor (T2) 1.6. 1 1 — Thermistor OK 0 — Thermistor Faulty Circ[...]

T able 18 — Sensor Resistance V alues TEMP (F) RESIST ANCE (Ohms) TEMP (F) RESIST ANCE (Ohms) TEMP (F) RESIST ANCE (Ohms) −60 362,640 45 1 1,396 150 1,020 −55 297,140 50 9,950 155 929 −50 245,245 55 8,709 160 844 −45 202,841 60 7,642 165 768 −40 168,250 65 6,749 170 699 −35 139,960 70 5,944 175 640 −30 1 16,820 75 5,249 180 585 −2[...]

Operating Sequence — The sequence presented be- low assumes that the unit is equipped with heat for morning warm-up and an economizer . If these items are not enabled with the appropriate DIP switches, the processor bypasses these subroutines. This sequence is also based on an EPROM (erasable, programmable, read-only memory) processor chip with t[...]

SIZE 044 UNITS — These units have 2 compressors and 1 unloader on compressor no. 1. See Fig. 42 for compressor and condenser fan motor locations. The unit operating se- quence is as follows: Stage 1 Relays K1 and K3 are energized. Compressor no. 1 starts with the unloader energized. Com- pressor no. 1 is running at 1 ⁄ 2 capacity . The crank- c[...]

074, 078 UNITS 054, 064 UNITS 088, 104 UNITS 054-088 UNITS 104 UNITS Fig. 43 — Component Arrangement, 054-104 Units 37[...]

Supply Fan Control with IGV — In most V A V units, the supply fan static pressure is controlled by inlet guide vanes. The inlet guide vanes operate independently from the micro- processor . The supply static pressure is controlled by a dif- ferential pressure switch. If the unit is equipped with a re- turn fan, building pressure is controlled by [...]

Fig. 44 — Modulating Power Exhaust Component Locations; Sizes 034-048 39[...]

Fig. 45 — Modulating Power Exhaust Component Locations; Sizes 054-104 40[...]

Fig. 46 — Modulating Power Exhaust Return End Sheet Metal Skin Detail; Sizes 034-048 Fig. 47 — Modulating Power Exhaust Return End Sheet Metal Skin Detail; Sizes 054-104 41[...]

T able 19 — Compressor Loading and Unloading Sequences COOLING ST AGE SIZE 034 UNITS Lead Circuit Lag Circuit Active Cylinders Percent Capacity Comp 1 Unloader U1 Unloader U2 Comp 2 0 OFF OFF OFF OFF 0 0 1 ON ON ON OFF 2 17 2 ON ON OFF OFF 4 33 3 ON OFF OFF OFF 6 50 4 ON ON ON ON 8 67 5 ON ON OFF ON 10 83 6 ON OFF OFF ON 12 100 COOLING ST AGE SIZ[...]

T able 19 — Compressor Loading and Unloading Sequences (cont) COOLING ST AGE SIZE 054 UNITS Lead Circuit Lag Circuit Active Cylinders Percent Capacity Comp 1 Unloader U1 Unloader U2 Comp 2 0 OFF OFF OFF OFF 0 0 1 ON ON ON OFF 2 20 2 ON ON OFF OFF 4 40 3 ON OFF OFF OFF 6 60 4 ON ON OFF ON 10 80 5 ON OFF OFF ON 12 100 COOLING ST AGE SIZE 064 UNITS [...]

TROUBLESHOOTING By using the display module, actual operating conditions of the unit are displayed while it is running. The Quick T est function allows proper operation of compressors, compres- sor unloaders, fans, and other components to be checked while unit is stopped. If an operating fault is detected, an alarm is generated and an alarm code(s)[...]

Diagnostic Codes — Diagnostic codes are warnings of abnormal or fault conditions, and may cause either one circuit or the whole unit to shut down. They are assigned code numbers as described below . T able 22 contains a description of each diagnostic code error and possible cause. Manual reset is accomplished by moving the ON/OFF Switch to the OF[...]

CODES 59 AND 60: LOW -PRESSURE SWITCH — These codes are used to indicate a low-pressure switch failure. The processor monitors the low-pressure switch. If the switch opens, either by low refrigerant charge, circuit failure, or wir - ing error , the circuit is locked of f. Code 59 indicates a failure of the lead circuit, and as a result, that circ[...]

Incorrect Potentiometer Setting — A potentiometer turned fully clockwise or counterclockwise is outside the valid range and will result in a failure. Faulty W iring — If the wiring between the potentiometer and the processor board is incorrect, a failure will result. Potentiometer Failure — If potentiometer is shorted or open, a failure will [...]

These 2 steps will help determine if a component other than a board is at fault or if the problem is external to control circuit. A volt-ohmmeter will be needed to troubleshoot boards. A digital meter is preferred but a Simpson 260 or equivalent will work. To prevent damage to solid-state electronic components on boards, meter probes should only be[...]

Step 5 — Check Relay Board Outputs from the Processor Board — This step involves checking the output signals from relays K1-K3 on the relay board. 1. T urn power to OFF position. 2. Connect negative test probe to TP19 (meter still set to dc). 3. T urn switch to ON position and enter Quick T est mode. 4. Connect positive test probe to terminal 1[...]

T able 24 — Pin T erminal Connector J1 V oltages PIN TERMINAL VOL T AGE (vdc ± 0.25 v) 1 2 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 Step 9 − Thermistor Input Connector Checkout 1. T urn power to OFF position. 2. Disconnect all plugs for pin terminal connector J2 and mark them for later replacement. 3. Con[...]

T able 27 — T erminal Strip J5 Connector Resistance Reading QUICK TEST STEP NO. J5 PIN NUMBERS 1234 5 1. to 2.5. ```` 0 2.6 00 `` 0 2.7. 0 ` 0 ` 0 2.8. 0 `` 00 2.9. to 3.3. 0 ``` 0 LEGEND ` — Infinity Step 2 — Check the Display LEDs 1. Enter Quick T est mode. 88 2. If is not displayed, replace display board. Step 3 — Check Set Point Potent[...]

Economizer Motor — All control of the motor (i.e., enthalpy changeover , minimum position control and mixed air control) is accomplished from the main unit microproces- sor through a relay board. Service and installation instruc- tions for the unit should be consulted to verify proper op- eration of these controls. The economizer motor may be che[...]

T able 29 — Carrier Default Program Parameter V alues P ARAMETER GROUP P ARAMETER DEF AUL T V ALUE SEtP (Setup) ACC1 60.0 Sec DEC1 60.0 Sec UL 60.0 Hz LL 10.0 Hz* Luln 1 P3 20% F-P3 0.0 Hz P4 100% F-P4 60 Hz tHr1 See T able 31 StC1 0 StL1 1 10% OLN 1 tYP 5* Gr .F (Fundamental) FH 60 Hz Pt 2 Gr .Fb (Feedback) FbP1 1* Fbln 2 GP .30 Gl 2 sec GA 0 GF[...]

VFD Operation — When troubleshooting the VFD, check first that all required conditions for VFD operation are satisfied. For the VFD to run, the following conditions must be met at the VFD: 1. Drive enable jumper is installed from terminals CC-ST (factory supplied) (see Fig. 53 and 54). 2. Proper rotation jumper is installed at terminals R-CC (r[...]

LEGEND AND NOTES FOR FIG. 55 ALM — Alarm C— Contactor CB — Circuit Breaker CCB — Control Circuit Breaker COMP — Compressor CH — Crankcase Heater CR — Control Relay DPS — Differential Pressure Switch DPT — Discharge Pressure Transducer EA T — Enering-Air T emperature EC — Enthalpy Control ECR — Economizer Close Relay EOR — [...]

Fig. 55 — T ypical Wiring Schematic; 48FK,JK and 50FK,FY ,JK,JY Units (054-074 Shown) 56[...]

Fig. 55 — T ypical Wiring Schematic; 48FK,JK and 50FK,FY ,JK,JY Units (054-074 Shown) (cont) 57[...]

SERVICE TRAINING Packaged Service T raining programs are an excellent way to increase your knowledge of the equip- ment discussed in this manual, including: • Unit Familiarization • Installation Overview • Maintenance • Operating Sequence A large selection of product, theory , and skills programs are available, using popular video-based for[...]

ST ART -UP CHECKLIST MODEL NO.: DA TE: SERIAL NO.: TECHNICIAN: I. PRE-ST ART -UP: M VERIFY THA T UNIT IS LEVEL M VERIFY THA T ALL P ACKING MA TERIALS HA VE BEEN REMOVED FROM UNIT M LOOSEN ALL SHIPPING HOLDDOWN BOL TS AND REMOVE SHIPPING BRACKETS PER INSTRUCTIONS M VERIFY THA T COMPRESSOR SUSPENSION SPRINGS HA VE BEEN LOOSENED PER INSTRUCTIONS M VER[...]

III. ST ART -UP CHECK EV APORA TOR F AN SPEED AND RECORD. CHECK CONDENSER F AN SPEED AND RECORD. AFTER A T LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS: COMP A1 COMP A2 COMP B1 COMP B2 OIL PRESSURE SUCTION PRESSURE SUCTION LINE TEMP DISCHARGE PRESSURE DISCHARGE LINE TEMP ENTERING CONDENSER AIR TEMP LEA VING CONDENSER AIR TEMP EV[...]