4-line by 40-character keypad / display or by using an IBM compatible computer running McQuay Monitor software. In addition to providing all normal operating controls, the MicroTech controller monitors all safety devices on the unit and will take corrective action if the chiller is operating outside of it’s normal design conditions.
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“on” time expires, the remote stop switch is opened, the system switch is moved to the stop position, or a separate communications panel such as the Chiller System Controller or an Open Protocol interface disables the chiller. PFS 155C - 315C OM 135...
Under menu 7 of the keypad place the unit into the automatic mode. Place the front panel switch into the auto position. Make the remote start / stop input. Superheat is factory adjusted to maintain between 1° and 10°F (1° and 7°C). OM 135 PFS 155C - 315C...
Make certain that circuit breakers are in the "off" position. Make certain control panel rocker switches are in "stop" position. Place main power and control circuit disconnects in ”on” position. Allow the crankcase heaters to operate for a least 12 hours. PFS 155C - 315C OM 135...
The compressor is checked at the factory for minimum vibration of 0.14”/second (3.56mm/ second) at 3500 rpm (2917 rpm). The compressor is supplied with a lifetime oil filter. If a visual inspection shows possible restriction, then replace filter. OM 135 PFS 155C - 315C...
Lead-Lag McQuay PFS water cooled chillers alternate the sequence in which the compressors start to balance the number of starts and run hours. Lead-lag of the compressors is accomplished automatically by the MicroTech controller.
If the compressor is not loading properly check the solenoids to see if they are energized. A complete check will include a check of the MicroTech output, the wiring to the solenoid and the solenoid coil itself. OM 135 PFS 155C - 315C...
Pump all remaining refrigerant out of evaporator, compressors, and liquid line. Complete pump-down according to EPA refrigerant guidelines before opening the circuit. Servicing of the components may now continue. PFS 155C - 315C OM 135...
The position of the valve can be viewed at any time by is using the MicroTech keypad through menu 3 (circuit pressures). There are a total of 760 steps between closed and full open. OM 135 PFS 155C - 315C...
If the unit is slightly undercharged the unit will show bubbles in the sightglass. Recharge the unit as described in the following charging procedure. PFS 155C - 315C OM 135...
MicroTech. Also, the compressors have a solid-state Guardistor™ circuit which provides motor over temperature protection. The Guardistor™ circuit has automatic reset but must also be reset through MicroTech. OM 135 PFS 155C - 315C...
L1, L2 and L3. Correct rotation is required for compressor operation. If required to do so by phase sequence, turn off the power and interchange any two of the supply power leads at the disconnect. Turn on the power. The output relay should now close after the appropriate delay. PFS 155C - 315C OM 135...
LCD type for easy viewing in all lighting • Building Automation System communication conditions. capability via McQuay’s Open Protocol strategy to • Two levels of security protection against over 10 major BAS manufacturers. unauthorized changing of setpoints and other •...
ADI Board and sends commands to the Output Board to maintain the unit's optimum operating mode for the current conditions. Status lights are mounted on the control board to indicate the operating condition of the microprocessor. OM 135 PFS 155C - 315C...
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Step through all of the unit’s setpoints by using the keypad / display and adjust them as required to meet the specific job requirements. Any faults appearing on the display should be cleared at this time by pressing the clear key. PFS 155C - 315C OM 135...
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LED's are furnished on the board to give a visual indication of the status of all digital inputs. All analog and digital signals from sensors, transducers and switches are received by the ADI Board and then sent to the Microprocessor Control Board for interpretation. Figure 4, ADI board OM 135 PFS 155C - 315C...
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VDC signal that is directly proportional to the chiller amp draw. The amp draw signal is sent to the ADI board for conditioning and then to the M280 controller. Figure 6, Signal converter board PFS 155C - 315C OM 135...
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The Keypad/Display is the primary operator interface to the unit. All operating conditions, system alarms and setpoints can be monitored from this display and all adjustable setpoints can be modified from this keyboard if the operator has entered a valid operator password. OM 135 PFS 155C - 315C...
The keys in this group provide quick access to strategic menus throughout the menu tree- structure. This reduces the need to step through all the menus, one by one, in order to reach the desired information. PFS 155C - 315C OM 135...
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Note: When Menu #1 is currently in the display (the first menu in the menu tree-structure), pressing "PREV." causes an "beginning of menus" message to appear in the display. Previous Menu Pressing "PREV." shifts the display to the previous menu. OM 135 PFS 155C - 315C...
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Pressing "ALARMS" followed by "CLEAR" clears the current fault. Also, when a change is made to a menu item, pressing "CLEAR" returns the display to the original value as long as "ENTER" has not yet been pressed. PFS 155C - 315C OM 135...
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Either U.S. Customary or S.I. engineering units may be displayed by installing the appropriate controller software. U.S. Customary Units: Temperature = º F (Fahrenheit) Pressure = (Pound per sq. inch) Psig Psid S.I. Units: Temperature = º C (Centigrade) Pressure = (Kilo Pascals) kPag kPda OM 135 PFS 155C - 315C...
Most menus will have only one screen. The range of information that can be displayed in a field is extensive and the next section will show all possible field names, setpoints and values. PFS 155C - 315C OM 135...
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Item Screen Line Display Field Range OffAlarm Motor Amps = x% Starts = Compr Hours Suction Line = x °F Discharge = x °F Suct Suprht = x °F Dsch Suprht = x °F PFS 155C - 315C OM 135...
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Saturated Cond= x psi Liquid Line = x psi Filter DP= x psi LiqSubCool = x °F Cond Apprch = x°F WaterPresRatio= Evap apprch = x°F RefrgPresRatio= Lift Press = x psi Table continued on next page OM 135 PFS 155C - 315C...
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(Chiller Setup). Item Screen Line Display Field Range Cooling Tower Stage=x Entering Condenser Water Temp=xx.x Coolg Tower Bypass Valve 0-100% Pos=xxx% 2 (*) Outdoor Air=xx.x * Requires optional Outdoor Air Sensor field installed by others. PFS 155C - 315C OM 135...
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Service Testing - This mode shuts down the chiller and the chiller is in the manual off mode. Menu 17 (Service Testing) allows the service technician to check the individual outputs and calibrate the selected transducers. OM 135 PFS 155C - 315C...
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Chw Reset= There are several methods that can be selected to reset the leaving evaporator chilled water temperature. No Reset - This does not provide any reset and is the default value. PFS 155C - 315C OM 135...
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The 4-20 mA signal limits the capacity of the chiller and saves electrical demand charges. Menu 10, Set Time/Date Item Screen Line Display Field Range Time Day Month and Year OM 135 PFS 155C - 315C...
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#4=N/A-00 00 Day(s) Jan-Dec 00-31 00-31 #2=N/A-00 00 Day(s) Jan-Dec 00-31 00-31 #5=N/A-00 00 Day(s) Jan-Dec 00-31 00-31 #3=N/A-00 00 Day(s) Jan-Dec 00-31 00-31 #6=N/A-00 00 Day(s) Jan-Dec 00-31 00-31 Menu continued on next page. PFS 155C - 315C OM 135...
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Stop-Start= This value is similar to the Start-Start already described. This time ensures that there is adequate time between stop to start for the chiller to become stable or pressures to equalize. This can also be used to minimize short cycling. OM 135 PFS 155C - 315C...
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Valve Spt= This value is the water temperature the MicroTech will maintain by modulating the tower valve. Valve Deadb= This value is the control dead band that is used in the MicroTech when calculating control actions. PFS 155C - 315C OM 135...
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HotGas Timr = x min Low Load = x °F Lo Load Tmr = x min Manual Pumpdown = No PumpDn EvapP = x psi Evap Offset=x.x psi 1-20Min PmpDn SuperHt=40 0-100 Cond Offset=0.0psi -9.9 - 15.0psi OM 135 PFS 155C - 315C...
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Changing the values in this menu can cause network communications failure. Item Screen Line Display Field Range Config=L2-TTY-Slave L1-TTY-Mastr L1-TTY-TTY L2-Mastr-Slv L2-TTY-Slave L3-TTY-Slave IDENT=FLU2E-01-I Port A Baud =9600 1200 2400 9600 Chiller Only Only /Templifier Menu continued on next page OM 135 PFS 155C - 315C...
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Cond Gpm Sensor= Optional. This value defines if a flow sensor is present for the MicroTech to monitor. Cond Full Gpm= This value defines the full flow capabilities of the condenser flow sensor. The MicroTech scales the value linearly between 4 and 20 milliamp input or 0 to 10 Vdc input. PFS 155C - 315C OM 135...
5. Inadequate liquid to liquid injection during run 5. Check liquid injection line sightglass If flashing check filter-dryer and unit charge Discharge pressure too low Troubleshooting chart continued on next page OM 135 PFS 155C - 315C...
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High Suction Pressure 24. Excessive load - high water temperature 24. Reduce load or add additional equipment. 25. Superheat is too low. 25. Check superheat on MicroTech display. Check suction line sensor installation and sensor. PFS 155C - 315C OM 135...
Eddy current test --tube wall thickness Seasonal protection KEY: O = performed by in-house personnel X = performed by qualified HVAC service personnel # = Test to be performed with compressor circuit in operation OM 135 PFS 155C - 315C...
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Note: Some motors use power factor correction capacitors and others use a surge capacitor. In all cases, capacitors must be disconnected from the circuit to obtain a useful megohmmeter reading. Failure to disconnect capacitors will result in low readings. Only qualified electrical technicians should perform service. PFS 155C - 315C OM 135...
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