DRAKE MCS-MicroMag User manual

www.drakechillers.com
2900 Samuel Drive | Bensalem, PA 19020
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MCS – MicroMag
Error / Alarm
Manual

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
Table of Contents
General Troubleshooting .........................................................................1
Microprocessor Features.........................................................................2
Display Features.......................................................................................3
Unit States.................................................................................................4
PowerUpDelay.........................................................................................4
OFF SCHEDULE .....................................................................................4
OFF RUN/STOP ......................................................................................5
COOLING ................................................................................................5
MACH LOCKOUT....................................................................................6
PUMP ONLY............................................................................................6
Alarms .......................................................................................................7
Supply Freeze..........................................................................................7
Low Suction Superheat............................................................................8
High Discharge Pressure.........................................................................9
Low Discharge Pressure........................................................................10
Low / Unsafe Suction Pressure..............................................................11
No Flow..................................................................................................12
Phase Loss............................................................................................13
No Battery..............................................................................................14
Sensor Fault...........................................................................................15
Appendices .............................................................................................16
Appendix A: Cooling States....................................................................16
Appendix B: Diagnosing Sensor Errors..................................................17
Appendix C: Phase Monitor Faults.........................................................21
Appendix D: Enter Password and Enable Run / Stop.............................23
Appendix E: Change Date / Time...........................................................25
Troubleshooting Notes...........................................................................27

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1 | Page
MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
1. Before calling Drake, make sure you:
a. Have ready:
i. Chiller’s serial number (located on
the exterior of the chiller, inside the
electrical panel door, and, on the
sticker shown to the right)
ii. Multimeter
iii. Ambient readings, temperature
probes, and pressure transducers
iv. Small flathead screwdriver
v. Laptop, for in-depth diagnostics
using MCS-Connect
vi. An RS-485 to USB cable (shipped
in the manilla folder with the chiller)
b. Check all fuses
c. Check fluids
i. Verify freeze point
ii. Check tank level
d. Make sure unit is correctly wired and
receiving power matching that found on the
data tag
2. For component locations, refer to the included
wiring and piping diagrams
WARNING!
Make sure to shut down AND disconnect chiller, waiting for ALL
displays or indicator lights to turn off, BEFORE making wiring
changes or replacing fuses
Failure to follow could result in serious injury or death
General Troubleshooting

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
Microprocessor Features
Standard Features
•Operates within +/- 0.1°F accuracy
•Powered from chiller 24 VAC (or 12 VDC) control circuit, eliminating high voltage
interference
•Dual-circuit control capability
•Can be set up to use either °F or °C and PSI or Bar
•Can control chiller using inlet or outlet temperature
•Compressor short-cycling reduction to increase compressor lifespan
•Compressor pump-down capability
•Alarm lockouts for chiller protection
•Automatic compressor lead-lag on dual circuit chillers
•Basic chiller functionality for easy setup and operation
•Custom factory configurations
oProgrammable for VFDs
oProgrammable for EC fans
•Two RS-845 serial communication ports
•Can communicate with Modbus RTU or BACnet MSTP
•Wet contact supply for field-installed Run / Stop switch
•Dry contact for alarm output
•Scheduled shutdown capabilities
•Integrates with MCS-Connect, a simple, free to use chiller monitoring computer software
10 Sensor Inputs
(INPUTS – SI)
RS485 Serial
Communication
24 VAC Input
(optional 12VDC)
2A 250V
Mini Fuse
6 Relay Outputs
(OUTPUTS - RO)
5 A 250V
Mini Fuse
12 VDC Output
4 Analog Outputs
(OUTPUTS – AO)

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
Standard Features
•LED-backlit display with a 6-button navigation menu
oDisplays current unit status and lockout alarms
oDisplays full range of sensor inputs, relay outputs, and setpoints
oSuction / discharge pressure and superheat monitoring
oMonitors compressor runtime and cycles per day
•Data logging capabilities, setpoint changes, and sensor calibration
•Alarm history of previous 99 alarms and events
•Capable of extracting data from the last 90 minutes of runtime
•Password authorization for setpoint changes
•NEMA4 gasket seal for extreme weather protection
Note
Any and all changes, modifications, and alarm
resets require a supervisor password (2112) to be
entered first
Display Features
LCD Backlit
Display
6 Button
Menu Keypad

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
A 60-second delay during chiller startup in which
all Relay Outputs are shut off and ensures the
board is receiving stable power.
When the unit is shut off due to a user set
schedule, the unit displays this status. In this state,
all relays are disabled, and their statuses will read
“OFF.” The schedule can be viewed or modified in
the Service Tools menu.
PowerUpDelay
1.
OFF SCHEDULE
MicroMag Unit States
2.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This status is displayed when the Run/Stop Switch
has been turned off. In this state, all relays are
disabled, and their statuses will read “OFF.”
To enable the Run/Stop, refer to Appendix D.
When the fluid inlet or outlet temperature sensor
reads a value higher than the value of Setpoint #8
(CWIN/OUT Target), the unit displays this state and
is starting to or is currently running in order to drop
the fluid temp below the setpoint. For cooling sub-
states, refer to Appendix A.
MicroMag Unit States
OFF RUN/STOP
COOLING
3.
4.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This state is entered whenever a critical situation
is encountered that could cause harm tothe chiller.
In this state, all RelayOutputs except the alarm are
turned off and will read “LOCKOUT.”
Lockouts can be reset from the keypad or with the
MCS-Connect program; however, if the lockout
condition has not been corrected, the system will
again be forced into this state.
Note - If the Lockout Reset is used more than 6
times in one day, the unit cannot be reset except
with Factory authorization. Call Drake for support.
This state is entered when all compressors have
been shut down, either due to normal operating
conditions or due to a lockout, and only the chilled
fluid pump is running.
MicroMag Unit States
MACH LOCKOUT
PUMP ONLY
5.
6.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the fluid out temperature drops
below the value of Setpoint #86. The chiller will
lockout and all Relay Outputs will be disabled to
avoid damage to the chiller.
Note: Supervisor password (2112) is
required to reset lockouts
Possible Causes
Solutions
Sensor fault on fluid out See Appendix B to troubleshoot
Setpoint #86 is incorrect
for operating conditions
Change setpoint to a lower value
IMPORTANT! If supply fluid is water, do NOT change setpoint to a
value lower than 40°F (4.5°C) as the liquid may freeze and cause
severe damage to the chiller!
Ambient temperature is
cold enough to affect
fluid temperatures
Verify insulation thickness is suitable for the lowest ambient
operating temperature
Add more glycol to lower freezing point, and then adjust Setpoint
#86 accordingly
Lack of flow through the
evaporator
Check that all valves are opened and that
there are no blockages or restrictions in the y-
strainer (shown to the right) or process
plumbing
Supply Freeze
MicroMag Alarms
1.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the suction superheat falls
below the value of Setpoint #67 for an allotted
time. When suction superheat drops too low,
liquid
refrigerant could enter the compressor,
causing damage. If the compressor has low
suction superheat, a LOW SUCT SPHT alarm
will display. The unit will attempt to run again
after a few minutes, but another trip within the
next hour will result in a lockout.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes Solutions
Sensor fault on suction
pressure or temperature
See Appendix B to troubleshoot
Lack of a load Verify the chiller has a heat load
Lack of fluid flow
Confirm active flow to the chiller
Ensure y-strainer (shown to the right) and
process plumbing are free of blockages or
restrictions, and that all ball valves are
opened
TXV
Verify superheat reading with physical gauges
Adjust the TXV (shown to the right)
Replace if needed
Refrigerant Overcharge Contact Drake
Low Suction
Superheat
2.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the discharge pressure rises
above the value of Setpoint #70. If the compressor
has high discharge pressure, it locks out the
compressor and the HI DIS PSI alarm will display.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes
Solutions
Sensor fault on
discharge pressure
See Appendix B to troubleshoot
Condenser panels
removed
Replace the panels on the chiller
Condenser dirty or
damaged
(Air-cooled)
Clean or replace condenser coils
(shown to the right)
Condenser blocked
(Air-cooled)
Poor installation location (overhang, other equipment installed too
close, wall, fence or other object is within 3’ of the chiller blocking
airflow
Fans not running
(Air-cooled)
Verify fuses are not blown
(left picture)
Carefully, with ONLY an
insulated screwdriver, bump
the condenser contactor at
the circled spot to see if fans
turn on (right picture)
Restriction in cooling
water
(Water-cooled)
Confirm that all valves are opened
Adjust regulator (shown to the right)
Refrigerant Overcharge
Contact Drake
High Discharge
Pressure
3.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the discharge pressure
drops below the value of Setpoint #69. If the
compressor has low discharge pressure, it will
lockout and display the LO DIS PSI alarm.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes
Solutions
Sensor fault on
discharge pressure
See Appendix B to troubleshoot
Condenser fans not
cycling properly
Check Setpoint #17 to ensure enough head pressure is being built
Flooded head pressure
controls (Receivers
only)
Adjust the ORI valve (shown to the right) for a
higher receiver pressure setting
Refrigerant charge is
low
Check for refrigerant leak
Contact Drake to determine the charge
Low Discharge
Pressure
4.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
The low suction pressure alarm will trip if the
suction pressure drops below the value of Setpoint
#62. If the compressor has low suction pressure, it
will lockout and display the LO SUC PSI alarm.
The unsafe suction pressure alarm will trip if the
suction pressure drops below the value of Setpoint
#64. This alarm warns of critically low suction
pressure and will lockout the compressor on that
circuit.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes
Solutions
Sensor fault on suction
pressure
See Appendix B to troubleshoot
Liquid line
blocked/restricted
Check that all valves are open between the
condenser and TXV, and that filter dryer
(shown to the right) is not blocked
Ensure TXV is opening and is set properly
Lack of load/flow
Ensure y-strainer (shown to the right) and
process plumbing are free of blockages or
restrictions, and that all ball valves are opened
Ensure heat load is present
Setpoint #62 is incorrect
for operating conditions
Check with Drake, then change setpoint to a lower value
Defective TXV valve
Shut down system, fully backseat TXV (shown
to the right), then front-seat TXV. Set TXV back
to the operating position. If operating problems
persist, call Drake
Refrigerant charge is
low
Check for refrigerant leak
Contact Drake to determine the charge
Low / Unsafe
Suction Pressure
5.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the Flow Switch on the
evaporator detects no flow for the allotted amount
of time (Setpoint 120). With this alarm tripped, the
compressors will each shut down until flow is
reestablished.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes
Solutions
Flow switch is not
reading
The flow switch (top photo) is out of
adjustment. Isolate, then remove from
the pipe and clean sensor
Air is present in the chilled fluid lines.
Purge air from the system
No fluid in the tank or low fluid levels
Ensure y-strainer (bottom photo) and
process plumbing are free of blockages
or restrictions, and that all ball valves are
opened
Check for a loose wire on flow sensor
terminal block, and check that MicroMag
is outputting 5VDC
Pump not operating
correctly
Verify pump is running
Check for any blown fuses (left photo)
Verify that the overload relay has not
been tripped (right photo, reset button
circled)
Check pump phasing to ensure it is
rotating in the proper direction
No Flow
6.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the chiller has lost phase,
forcing the chiller to temporarily shut down until any
faults are cleared on the phase monitor.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes Solutions
Problem with 24VAC
Check transformer output to make sure it is
outputting 24VAC to the phase monitor. If
not, make sure the transformer inputs are
set up for the correct line voltage
Verify that all wires are connected securely
to the transformer and to the phase monitor
Check for any blown fuses (left photo)
Problem with 5VDC
MicroMag output
Ensure MicroMag is outputting 5VDC from the sensor terminal
If MicroMag is not outputting 5VDC, call Drake for assistance
Fault on Phase Monitor See Appendix C to troubleshoot
(Phase monitor is shown to the right)
Phase Loss
7.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will trip if the internal battery has run dry
or if it has been removed.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes Solutions
Battery on MicroMag
missing or depleted
Reinstall or replace the
battery (location shown to
the right)
(BR2032 or CR2032 coin
cell battery)
Time and date are
inaccurate
Adjust the date and time (see Appendix E)
No Battery
8.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
This alarm will occur whenever a sensor input is
not receiving any feedback from its sensor. If a
sensor or wire is disconnected from the MicroMag,
the input will read -99.9 and if a sensor is shorted,
it will read 999.9.
Note: Supervisor password (2112) is
required to reset lockouts
MicroMag Alarms
Possible Causes
Solutions
Sensor fault See Appendix B to troubleshoot
Sensor Fault
9.

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
•COOL INIT - Cooling is in initialization mode
•UNLOADING AZ - We are above the zone
and unloading (ROC)
•LOADING AZ - We are above the zone and
loading (normal)
•HOLDING AZ - We are above the zone and
holding (ROC)
•UNLOADING BZ - We are below the zone
and unloading (normal)
•LOADING BZ - We are below the zone and loading (ROC)
•HOLDING BZ - We are below the zone and holding (ROC)
•UNLOADING IZ - We are in the zone and unloading (ROC)
•LOADING IZ - We are in the zone and loading (ROC)
•HOLDING IZ - We are in the zone and holding (normal)
•UNLD ROC - We are unloading based on ROC
•LOAD ROC - We are loading based on ROC
•HOLD ROC - We are holding based on ROC
•OFF & READY - The cooling is off but ready to run
•DISABLED - The cooling is disabled
•NO FLOW - The cooling is off because there is no flow
•LOCKED OUT - The cooling is locked out
•SUPERVISOR - We are in supervisor mode
•HOLD PCOOL - We are in pre-cooling and holding
Appendix A
Cooling States

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MCS – MicroMag Error / Alarm Manual
Version: 02/21/2020
Pressure Sensor
1. Check sensor inputs. If the sensor is reading
a value of -99.9 (sensor or wire
disconnected, the value is shown to the right)
or 999.9 (shorted wire), jump to step 2b
2. Verify sensor accuracy
a. Verify sensor with refrigerant
pressure gauges
b. Ensure the MicroMag is outputting
+5VDC at the “+5” sensor input port
(measured between “+5” and “ “)
c. Make sure sensor is set to analog “A”
3. Check for loose wire on sensor terminal
block of MicroMag and verify wiring is in the
correct sequence (see Sensor Wiring section
on page 19)
4. Check the sensor cable for any signs of
damage
5. Ensure sensor harness is securely
connected to pressure transducer
6. Verify that pressure sensor is completely
screwed into Schrader valve on the pipe
7. Check to make sure Schrader valve is
depressing
8. Call Drake for assistance
Appendix B
Diagnosing Sensor Errors
4
5
1
6, 7
Pressure
Transducer
2.b, 3
2.c