NRL

The information can be accessed only by properly identifying the unit. The full Aermec model number, serial number, and comm. Numbers are required to identify wiring and components. Communications between the distributor and service mechanics can be made by contacting us at the following telephone or e-mail addresses.

The GR03/GR3 controller user manual can be used to set up all stand-alone and BMS installations which will operate with standard environmental conditions. Do not attempt to adjust the control parameters without having read and understood the manual. The NRL unit arrives with a basic operating program ready to start up as soon as the building utilities are completed. The GR3 user manual allows you to understand the basic functions and set points required to operate the system. For more complex systems the GR3 after service manual is available to provide additional information. In the interest of brevity the GR03/GR3 may be described as GR3 where it is appropriate.

The Aermec GR3 user manual can be downloaded at Aermec.us. The Aermec after sales service manual can be downloaded from Aermec.us

The GR3/GR03 service information can be found in the GR3 after sales service manual in two parts the first 115 pages describe the setup for r-407c, the remaining pages describe the GR3 parameters for r-410a.

The GR03/GR3 control system consists of two components which are the GR03 display screen touchpad and the GR3 control module. All changes to the factory set operating parameters are completed by configuring the two sets of dipswitches and installing set of terminal jumpers (bridges). Then the soft valves can be inputted into the controller through the GR03 display screen pad. NRL systems that are to be monitored by a BMS can also be modified remotely by a computer if the appropriate switches and jumpers have been installed. These setting checks and adjustments are considered to be part of the basic start-up procedure.

Power up the line voltage wiring 24 hours before start up to allow the oil to warm up and drive off any refrigerant in the compressor oil. In the event line voltage power is off for any length of time during the unit’s normal service life (for more than four hours) allow the unit to warm up the oil for 1/2 hour for each hour off line.

Refer to Aermec chiller start up procedure form doc. 061103. Make sure all hydronic, electrical and refrigerant checks have been completed. Check to make sure the hydronic system is pressorized to 1.5 bar (21 PSIG) and that all isolating valves are fully open between the unit and load.

If a remote pumping station is used.  Make sure that the pump is on and rotating in the correct direction to pump water through the system. Water flow must be established.

Using the local / remote switch toggle to the local position. The green led light will turn on. Using the mode button toggle the switch to heat or cool as required. The green led will turn on and indicate the working mode. Push the start button on the GR03 display keypad for five (5) seconds. The led will come on and indicate the new unit status. The unit will begin to start up if in local mode and no accessory controls have been added.

Optional controls include the pr3, the PRD1, supernode / BMS with accessories, microchiller / BMS with accessories and multichiller/ BMS with accessories. NRL units equipped with BMS controls must be switched from local to remote after startup for the first time.

Push the alarm button (red bell) once to see the latest error code.

Record same push the alarm button (red bell) again to see 2^nd last error code.

Record same scroll through historical listed error codes.

(CP1 power, CP1A power, CP1B power, CP2 power, CP2A power, CP2B power)

Parameters CP1 power to CP2B power (up to 6 steps) can be used to shut down an individual compressor requiring service or for reasons. The compressors % of load number must be changed to zero. The GR3 will not look for the compressor which has a 0 % service value set into this function. All general and safety controls directly related to this specific compressor only will be overlooked. All other compressors showing a unit % will run and operate as needed.  Upon completion of the service for the compressor requiring shut down return the power parameter % to its normal value. The compressor will start up in the next cycle.

(CP1, CP1A,CP1B, CP2. CP2A, CP2B, 111111)

Parameters CP1 to CP2B (up to 6 steps) can be used to shut down an individual compressor requiring shut down for load shedding purposes. Each compressor up six is identified by a 1 in the number string 111111. The individual compressor will not start up if its identifier has been switched to 0 unless contact m11 3-4 is closed. If the remote contact m11 3-4 is open all other compressors identified by 1 will operate. This parameter is useful when starting compressors during the service checks.

(MP1, MP1A, MP1B, MP2, MP2A, MP2B, RMV1, RMV2)

If any of the compressor protection (wired in series) devices trip the safety circuits M9.1 to M9.2 or M12.1 to M12.2 is opened shutting down the NRL circuit completely. A solution is to disconnect the defective compressor or control electrically. Install a jumper on the overload or relay control contacts. All other unit functions should be operational.

(MT(V)1, MT(V)1A, MT(V)1B, MT(V)2, MT(V)2A, MT(V)2B, RMV1, RMV2)

If any of the fan protection (wired in series) devices trip the safety circuits M9.1 to M9.2 or M12.1 to M12.2 is opened a solution is to disconnect the defective motor or control electrically. Install a jumper on the overload or relay control contacts. Seal off the fan opening with a sheet of plastic. Reset the GR3 the NRL should start up with one fan disengaged. All other unit functions should be operational.

All 60 cycle NRL’s are equipped with an AP (HP) transducer which provides an analogue signal to the gr3 controller. The trip point for the AP (HP) transducer can be adjusted from downward from 39 bar (566 PSIG). To suit site conditions. The manual AP (HP) reset control cuts out at 41 bar (595 PSIG) and must be physically reset.

The hot gas temperature (HGT) cut-out switch is mounted on the discharge line. It will trip if the HGT exceeds 135 deg. C. (275 deg. F.) On earlier models the hot gas temperature switch (HGT) was wired directly in series with the manual high pressure relay contacts rap1. On later models the wiring has been moved to be in series with the compressor motor contactor will show up on the wiring diagram but not on the gr3 display as being tripped. The HGT differential is 20 degrees Celsius before automatically resetting.

All 60 cycle NRL’s are equipped with a BP (LP) transducer which provides an analogue signal to the GR3 controller. The manual low pressure switch is optional.

Chillers, free cooling units, heat pumps

The low pressure and high pressure transducers can be removed from the system without removing the charge from the system as they are fitted with a schraeder check fitting. Units that are fitted with a low pressure switch from the factory are also equipped with a schraeder check valve. By code the manual high pressure switch is not fitted with a schraeder check valve. See below for further details on changing the AP (HP).

Chillers and free cooling units only, not for heat pumps

Close the liquid line valve. Pump down the compressor section. Close the hot gas line. Reclaim the refrigerant trapped between the evaporator and hot gas line by accessing the schraeder valve in the hot gas line. Make the repairs. Pressure test. Evacuate the compressor section. Add a small charge of refrigerant to raise the pressure to one or two lbs. Open up the closed valves. Start the system. Check the refrigerant charge.

Heat pump units do not have isolating valves at the hot gas and liquid lines. Therefore any repairs on the refrigerant circuit at the compressor will require all of the refrigerant to be removed from the unit.

Chillers and free cooling units only, not for heat pumps depending on the model of the NRL the liquid line and discharge lines are equipped with isolating valves. The liquid line valve can be closed, the compressor section can be pumped down to one or two pounds, the hot gas line valve canbe closed. The remaining refrigerant pressure can be vented / reclaimed. The compressor is fitted with an oil siphon line that can be used to remove the oil. The new oil is to be recharged to the required sight glass level.  Evacuate the compressor section. Add a small charge of refrigerant to raise the pressure to one or two lbs. Open up the isolating valves and restart the unit.

Depending on the size of the NRL the liquid line and discharge lines are equipped with isolating valves. The liquid line valve can be closed, the compressor section can be pumped down to one or two pounds, the hot gas line valve can be closed. The remaining refrigerant pressure can be vented. The compressor repairs can be made as per good refrigerant practice. Evacuate the compressor section add a small charge of refrigerant to raise the pressure to one or two lbs.  Open up the isolating valves and restart the unit.

Chillers, free cooling units, heat pumps

Depending on the model of the NRL the liquid line and discharge lines are equipped with isolating valves. The liquid line the refrigerant charge must be completely replaced along with the liquid line filters in the case of a burnout. All of the oil in the unaffected compressors must be changed as well.

Chillers, free cooling, heat pumps

The factory approved repair is to replace the defective compressor only. The liquid line filters and oil will need to be replaced as required by the acid test.

The AP (HP) transducer is factory set to 39 bar (565 PSIG). The manual AP (HP) manual reset switch is set for 42 bar (609 PSIG). The AP (HP) relief valve is set to release refrigerant at 45 bar (652 PSIG). It is possible that the unit will totally shut down on (609 PSIG) the manual AP HP) switch. In order to avoid this situation and keep as much of the system running as long as possible in an AP (HP) situation the press f. Parameter in the gr3 control can be adjusted to shut down one compressor in a tandem circuit. If the AP (HP) pressure continues to rise the second compressor in the circuit will be shut down. If the AP (HP) condition remains the transducer will shut off the last compressor on the third (3) occurrence. If the AP (HP) transducer does not shut down the compressors; the manual AP (HP) switch will trip at 41 bar (609 PSIG). Shutting down the circuit permanently. The pre-alarm changes to a permanent AP (HP) alarm after three pre-alarms have occurred. This AP (HP) transducer adjustment will allow you to run the affected NRL circuit in a reduced capacity until the problem is resolved permanently. On start-ups we now recommend setting the parameter press f. To 32 bar when setting up the unit for the first (1) time.

Chillers, free cooling, heat pumps. 2 circuits up to 3 compressors per unit.

The press f. Parameter can also be used on units with as few as 2 compressors. The transducer will shut off one compressor.  Wait 5 minutes (time out). Then the GR3 will turn the compressor back on. If the AP (HP) problem has been resolved the GR3 will allow the NRL to run. The NRL will shut down permanently if the allowable three (3) pre-alarm intervention number has been exceeded. If not the GR3 will allow the NRL to start up and run.

GR3 test procedure:

1. 1. 1. Switch off the power to the unit
      2. Change the position of the sw2 dip switch # 4 to on.
      3. Change the position of the display dip switch 1 to 8 as follows on off on off on off on off.
      4. Turn the power supply back on.
      5. The two led’s beside the dip switches should indicate a
      6. Yellow flashing heart beat gr3 board is powered on
      7. Red flash communication error between gr3 and gro3 display.  On a start up for a few seconds

Answer the following questions after power up by using the up and down arrows for yes and no

1. 1. 1. Reset alarms recorded
      2. Reset default parameters
      3. Hardware test

Chillers and free cooling units only, not for heat pumps

Depending on the size of the NRL the liquid line and discharge lines are equipped with isolating valves. The liquid line valve can be closed, the compressor section can be pumped down to one or two pounds, the hot gas line valve can be closed. The remaining refrigerant pressure can be vented. The compressor is fitted with an oil siphon line that can be used to remove the oil.  The new oil is to be recharged to the required sight glass level. Evacuate the compressor section. Add a small charge of refrigerant to raise the pressure to one or two lbs. Open up the isolating valves and restart the unit.

Chillers, free cooling, heat pumps

The factory approved repair is to replace the defective compressor only. The liquid line filters and oil will need to be replaced as required by the acid test.

We use 2 heater of the code 6406802 in each plate. Each are 150W and 230V.