Unit installation

OMRCPMICRO 19
7 Cooling
Compressor 2
Unloader 1
Compressor 2
Unloader 1
Compressor 2
Unloader 1
8 Cooling Not Used
Compressor 1
Unloader 2
Compressor 3
Circuit 1
9 Cooling Not Used
Compressor 2
Unloader 2
Compressor 4
Circuit 2
10 Condenser Fan(s) M12
k
Same Same Same
11 Condenser Fan(s) M13
k
Same Same Same
12 Condenser Fan(s) M14
k
Same Same Same
13 Condenser Fan(s) M22
k
Same Same Same
14 Condenser Fan(s) M23
k
Same Same Same
15 Condenser Fan(s) M24
k
Same Same Same
Note: kCondenserless WHR only.
User selectable reset options are found under Menu 14, item line G "ResetOpt= " for chillers and item line H
"Reset Sig= ##.#mA" for Templifiers. Most reset options apply to leaving chilled water only—ALRs, WHRs,
and THRs operated in chiller mode. The only reset options available for THRs operated in heating mode
(controlled by leaving condenser water) are: "None", "4-20mA", and "Network". Selected reset option
settings for chilled and heated water temperatures are displayed in Menu 14.
None
"None" is the Default Values setting. When selecting "None", the following applies:
Ø Leaving evaporator water temperature or leaving condenser water temperature, whichever is applicable
control the unit.
Ø Leaving evaporator water temperature control ALRs, WHRs, and THRs operating in the "chiller" mode.
Ø Leaving condenser water temperature control THRs operating in "heat pump" mode.
Return
By selecting "Return" as the reset mode, the controller resets the leaving chilled water temperature set point as
required to maintain a constant return water temperature. To choose "Return" as the reset option, first select
"Return" in the "ResetOpt" mode and press <ENTER>, then in the "ReturnSpt" item, select the return water set
point temperature to be maintained. The return water set point algorithm is internal to the controller. No other
action is required.
4-20mA (remote reset signal)*
By selecting "4-20mA" as the reset option, the controller will reset the leaving chilled water temperature to a
higher value based on a percentage of the Maximum Chilled Water Reset ("MaxChWRst"). At 4mA, the chilled
water set point resets to a value equal the Leaving Evaporator Water Set Point ("Lvg Evap") plus the
MaximumChilled Water Reset ("MaxChWRst") set point. Any valuebetween 4 and 20mA will add a
proportional value of the Maximum Chilled Water Reset to the Leaving Chilled Water Set Point. The reset
schedule is linear and may be determined using Figure 7, Leaving Water Reset, below. The external 4-20mA
control signal displays under "ResetSig=" on Menu 14.
For THRs operated in heating mode, the "Lvg Evap" indicates the degree of heating reset. Using the 4-20mA
reset signal, a proportional value of the Maximum Chilled Water Reset "MaxChWRst" is subtracted from the
Leaving Condenser Water Set Point ("Lvg Cond" Menu #4). The reset control signal will display on Menu
#14, item line "Reset Sig". The reset schedule is linear and may be determined using Figure 7, Leaving Water
Reset, below.
Terminals #134 and #135 on TB7 are the field wiring 4-20mA remote reset terminal. See the field wiring
diagrams in the back of this manual for more detail.