User guide
Revision 7.1b Page 15 of 31
Mercury Coldroom Panel Installation Guide
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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
Parameters Description
Number
Parameter
Description
P-01
Cut-in Temp
Temperature at which the LLV or compressor will switch on
P-02
Diff
Differential temperature below the cut-in temperature. The LLV or lead compressor
switches off when below this temperature
P-03
Control Weight
Percentage of the Air-On temperature that is used to calculate the control temp. The
remaining percentage will be used on the Air-Off temperature
Example, P-03 set to 30%
Control temp = 30% Air-on + 70% Air-off
P-04
Display Weight
As above only applied to the display temperature
P-08
Superheat Ref
The EEV controller will attempt to maintain this superheat value
P-09
Response On
Allows the user to speed up the EEV on time. With 30 providing the quickest response and
1 providing the slowest response.
P-10
Response Off
Allows the user to speed up the EEV off time. With 30 providing the quickest response and
1 providing the slowest response.
P-11
Control Type
Allows the user to select either EEV control, EET control or EEV/EET control. Note the
Evaporator Temperature probe should be fitted to the coldest point in the evaporator.
EEV uses the superheat as its main reference with the cabinet temperature as a secondary
control.
EET use the cabinet temperature as its main reference.
EEV/EET uses cabinet temperature as the main control until the SH gets close to the SH
reference point, then it switches to EEV control, it switches back to EET control when the
SH reference is satisfied.
P-17
Evap select
Local – Uses local probes
Rem1 – Uses section 1 pressure from plant pack selected OR If no plant pack can use
Mercury Switch pressure
Rem2 - Uses section 2 pressure from plant pack selected
Rem3 - Uses section 3 pressure from plant pack selected
See: EEV Control using Pressure
P-51
EEV Min Opening
Sets the minimum valve opening level, during normal operation the valve will not go below
this level. (Default 10%)
IF used in conjunction with a Mercury Pressure Hub PR0018-PHI, remote pressure from
Plant Pack or local pressure from a daughter card, then the Minimum value should be set
at 0%
P-52
Superheat Problem
Sets the point at which the algorithm will go to the “EEV Problem” state due to the
superheat temperature. For example if this parameter is set to 0 Degrees and the
Superheat value falls to 0 degrees or below, for the duration of P-54, then the controller will
enter the superheat problem state.
P-53
EEV Problem Opening
Sets the valve open position when entering the “Superheat EEV Problem” state.
P-54
EEV Problem Time
Sets the time the algorithm stays in the “Superheat EEV Problem” state.
P-56
EEV Start Opening
Sets the valve opening % which is used after a defrost or when the controller exits a
problem state for, example Superheat EEV Problem state
P-55
Ave Valve Opening
Normally the valve during recovery will open to the last average position. This setting
allows for that value to be reduced by said percentage. For example if the average valve
opening is calculated as 80% and P-55 is set to 50% then the valve will open at 40%.
P-57
Div Value
This parameter only takes effect when the controller is used in conjunction with a Mercury
Switch pressure application. When the Mercury Switch generates the MOP alarm the
controller reduces the maximum valve opening to this percentage. For example if this
parameter is set to 50% and the MOP alarm is generated then the maximum valve opening
will be limited to 50%. Therefore as the controller pulses the valve the maximum the valve
will open is 50%.
Note P-51 EEV Minimum opening overrides the valve output operation and the valve will
not pulse below this setting.
Please see MOP note.
Please note parameters P-51 through to P-57 should not be altered without first
understanding the effects they may have on the case operation. If incorrectly set they may
have undesired affects.
P-85
Key switch mode
Not used on the coldroom panel.
P-87
Control Probe type
Switches between using the air-on probe or the logging probe. Note the control and display
temperature will still be a derivative of the weighted
Average of the control probe + Air-off probe
P-90
Resistor Case Off
Turns on/off the switched resistor case off function
P-92
Fans temperature mode
Allows the user to set the fans to turn off when: -
A pre-determined temperature is reached (P93)
When an over-temperature alarm is present