User guide

Revision 1.0 Page 15 of 29
Warning
Please Note
The specifications of the product detailed on this
Set-Up Guide may change without notice. RDM
Ltd. shall not be liable for errors or for incidental
or consequential damages, directly and indirectly,
in connection with the furnishing, performance or
misuse of this product or document.
Ensure that all power is
switched off before
installing or maintaining
this product
Mercury 3 M & E Installation Guide
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 Mode 1 – Case goes to “CO2 Load Shedding Case Off Mode”
 Mode 2 – Goes to Case Clean Mode
See: Load Shedding
P-100 /
P-101
Digital Input 1 /
Digital Input 2
Sets the status input type for the two Digital Inputs;
 Plant 1 – When the DI is activated, it would alarm Plant Fault 1.
 Switch – Would carry out the operation set on the ‘Key Switch mode’ (p-85)
 Defrost – The DI activation would signal the unit to go into a defrost (must be set to remote df).
 Door – The DI activation would signal if the door is open or closed.
 Man Trap – If the DI signal is received, it would activate a Man Trap alarm.
P-20
Alarm Delay
Delay for the over and under-temperature alarms
P-21
UT Alarm
Under temperature alarm set point. This alarm uses the control temperature.
P-22
OT Alarm
Over temperature alarm set point. This alarm uses the air-off temperature.
P-23
Log Probe Type
Allows the user to set the logging probe mode: -
 Off
 Logging with no alarms
 Logging with alarms
P-24
Slug Log Probe
Applies a damping factor. This can be used to make a standard probe have the same temperature
response as a logging probe.
P-25
Log Alarm Delay
Delay for the Logging probe over and under-temperature alarms
P-26
Log UT Alarm
Logging probe under temperature alarm set point
P-27
Log OT Alarm
Logging probe over temperature alarm set point
P-28
Monitor OT Alarm
Monitor probe over temperature alarm set point
P-40
Defrost Mode
Allows the user to set the defrost mode: -
 Local (Uses the internal parameters P-41 and P-42)
 Remote (Requires a defrost schedule in the front end)
 External (uses a switched resistor in input 1 (E) or 3 (M)). When this signal is present a defrost
is initiated.
Note: - If the external defrost signal is not removed then the controller will defrost according to the “No
Defrost” time and a missed defrost alarm will be generated. See P-29 for external defrost signal setup.
P-41
Defrost Start
When defrost mode is set to “Local”, this is the start time for the 1
st
defrost
P-42
Defrosts per Day
When defrost mode is set to “Local”, this is the number of defrosts per day equally spaced from the start
time.
P-43
No Defrost Time
If the controller misses a defrost command for any reason, a defrost will initiate after this time has elapsed
from the last defrost. Normally set to 2 hours over the normal defrost period.
P-44
Def Terminate
The defrost will terminate (defrost control relay off) when the temperature of the defrost termination probe
reaches this value.
If the "defrost termination" probe is not fitted, defrost termination will occur when: -
The "coil in" probe reaches the set point (If fans are selected as "off during defrost")
Or
The "air off" probe reaches the set point (If fans are selected as "on during defrost"). If the "coil
in" probe is not fitted, the "air off" probe will be used.
P-45
Def Min Time
Minimum time that a defrost will use (Defrost can’t terminate until this time has elapsed. If termination
temperature is reached during this period, the defrost control relay is turned off, but the controller will not
continue the defrost cycle until the end of the defrost min period)
P-46
Def Max Time
Time period after defrost minimum that defrosts are allowed to terminate
P-47
Drain Down
A period after defrost max to allow the draining of any surplus water
P-48
Recovery Time
The LLV is switched on at the start of this period to allow the temperature to recover to the normal
operating point. This period also inhibits the OT alarm.
Note that if the air-off temperature is still above the OT alarm setpoint when this period expires, an
immediate OT alarm occurs; there is not a further alarm delay.
P-89
Pump Down Time
Time period before the defrost min period to allow for a pump down
P-86
Fan Delay mode
This parameter allows the fans start after a drain-down period to be delayed, either by time (P-49) or
when the temperature point (P-88) is reached. This parameter uses the same probe strategy as the
defrost terminate.
P-49
Fan Delay
Time after a drain-down period before the fans start if P-86 is set to time
P-88
Fan Delay Temp
Temperature at which the fans start after a drain-down period when P-86 is set to temperature.
P-50
Fans In Defrost
Allows the user to set the fans on or off in defrost.
Note if the fans are set to on in defrost, they will go off for the drain-down period and then follow the P-86
rules.
P-94
Defrost Hold
Turns the defrost hold feature on and off. When switched on, the controller can be held in defrost until a
remote command from the front end starts the recovery process.
P-95
Defrost Skip
Allows user to enable/disable defrost skip. This feature allows the controller to skip defrosts. If the current
defrost terminates on temperature then the controller will skip the next scheduled defrost providing the
previous defrost terminated before the defrost skip time (P-96). Operates only when the controller is set to
local defrost scheduling.
P-96
Defrost Skip Time
Time factor used in defrost skip. The previous defrost has to terminate before this value expires to allow
the controller to skip a defrost.
P-91
Defrost Type
Electric – Defrost heater will go off during defrost min. period, if defrost termination is achieved, and will