FAQs

SIERRA

Temperature operating range:

Can a SIERRA compressor / controller be used in Low ambient environment?

We have not evaluated the controller for operation below 0°C (32°F) ambient, and unfortunately, we will not warranty a compressor/controller that is running in these conditions. Also, the pour point of the oil (PVE 68cSt) in the compressor is -35°C (-31°F). Below this temperature, the oil loses its flow characteristics, therefore the compressor must be maintained at temperatures above -35°C (-31°F) to assure proper oiling at startup. You can potentially employ a sump heater or enclosures. We recommend Tutco compressor heaters (Model #CH-184). For the application of a crankcase heater, a minimum of +5.6°C (42°F) must be maintained between the compressor sump temperature and the saturated condenser temperature.

Can a SIERRA compressor / controller be used at low condensing temperature?

At extremely low condensing temperatures (0-10°C) (14°F), it is necessary to be very careful with refrigerant charge. There is significant risk of liquid returning to the compressor which could result in flooding and or refrigerant in the compressor sump. Refrigerant in the sump can lead to premature bearing failure as the mechanism would be pumping liquid refrigerant to the bearing surfaces as opposed to oil.

Can a SIERRA compressor / controller be used at high condensing temperature / high ambient environment?

The SIERRA compressor can operate at condensing temperature above 65.8°C (150°F) or ambient above 50°C (122°F) for AC/HBP applications. However, it is important to realize that the compressor performance will be affected. The motor controller will shut down the motor if the heatsink temperature exceeds 100°C (212°F). The compressor shell temp must not exceed 150°C (302°F) to protect the compressor motor. High condensing temperatures can drive the shell temperature up and the application should not exceed the maximum compression ratio of 8:1.

As it is outside of our published operating conditions, we will not warranty a compressor/controller that is running in these conditions.

What are the typical housing temperatures reached by a SIERRA?

For reference, the typical compressor housing temperatures at max speed rating point conditions are as follows:

• TECUMSEH conditions - 7.2°C (45°F) Evaporator / 54.4°C (130°F) Condenser / 18.3°C (65°F) Return – 87.8°C (190°F) @ 24V, 93.3°C(200°F) @ 48V
• ARI conditions - 7.2°C (45°F) Evaporator / 54.4°C (130°F) Condenser / 18.3°C (65°F) return) – 79.4°C (175°F) @ 24V, 87.8°C (190°F) @ 48V Both conditions are measured using 425 cfm airflow over housing in a 35°C (95°F) ambient condition.

What type of compressor heater should be used with SIERRA and compressors?

• We recommend Tutco compressor heaters (Model #CH-184)

Where can I find PVE oil used in the SIERRA compressors?

• You can purchase the oil from a Nu-Calgon distributor
• http://www.nucalgon.com/products/oils/pve-lubricants

PVE Oil	Packaging Size	Part Number
FVC68D	6x1 Quart Case	4319-24

 

Compressor Application range:

Can a SIERRA compressor be used in an embedded application?

Our rotative compressors are built for mobile application with fixed mechanic. Our largest customer uses our compressors and controllers for cabin cooling in class 8 trucks. Our compressors and controllers have been evaluated against the attached internal vibration specifications (600A1144 & 600A1286). As for reliability, the compressors have been validated against Tecumseh’s Global 6 Specification, level 1 & 2.

Can a SIERRA compressor be used with solar panel application?

Yes, however, for solar application, it is important to be careful that the system does not exceed 60V. If there is a possibility, the 025A0198 controller needs to be used, as it has protection for these peaks.

Can a SIERRA compressor be used with AC power?

VAC input would have to be converted with a transformer, to DC power output. As long as the transformer is sized to the controller (voltage/current), it is not a problem.

What are the differences between a SIERRA17-0982Y3 (48V) and a SIERRA03-0982Y3 (24/48V)?

The SIERRA17-0982Y3 and SIERRA03-0982Y3 are different motor designs. The 17 - voltage code, is based off the 48/100V platform and affords better efficiency albeit at lower speeds and capacity than the 24/48V version.

What are the 24V High Capacity and High Efficiency features on the SIERRA03-0982Y3 models?

High Capacity Versions – Different motor construction to allow for higher speeds at lower voltage

High Efficiency Versions – Different motor construction to allow for reduced current draw with reduced speeds as the trade-off

Can DUAL compressors be used as SINGLE compressors?

A SIERRA DUAL compressor cannot be used as a single and must only be used with the configured DUAL controller

A SIERRA SINGLE compressor cannot be used with a controller configured in DUAL.

Also, Controllers are programmed for single compressor operation or dual compressor operation. They are not programmed for both.

What is the specificity of the SIERRA04-0982Y3 48/72 VDC?

These compressors are optimized to run with 72V. They can technically run the 48/100V range; however, they won’t be as efficient as standard 48/100V models.

What is the SIERRA compressor noise level?

We have measured SIERRA sound power levels at 60-65 dB for 3600 rpm and 70-75 dB for 6500 rpm. (weighted sound power values noted as LWA.) The sound values are measured at ASHRAE HBP rating point conditions - 7.2°C (45°F) Evaporator / 54.4°C (129.9°F) Condenser / 35°C (95°F) Suction / 35°C (95°F) Ambient.

Compressor start and maintenance

What is the SIERRA compressor limitation in the number of start/hours?

We ask our customers to tailor their applications to prevent excessive cycling of the compressor (>5 cycles per hour). Following this precaution, the Mean Time Before Failure (MTBF) of SIERRA compressors is 10 years.

What is the SIERRA Compressor start and oiling period?

There is a 30 second oiling period at startup where the compressor runs at 3000 rpm unless the voltage is too low to attain said speed. After the 30 seconds have elapsed, the compressor will run the commanded speed unless it is voltage or load limited. The oiling period occurs at every start-up if the voltage to the controller or the drive enable signal is interrupted. The oiling period is necessary to have a good priming oiling pump of the compressor. After this 30 second period, the compressor is able to run over its entire speed range.

What are the maintenance requirements for a SIERRA Compressor?

SIERRAs are hermetic compressors, there is no mechanical maintenance that can be performed on them. Assuming proper installation, the cooling system will only require general cleaning to ensure the airflow through the coils is not restricted, the housing is not in contact with anything that would prevent proper heat transfer, and there is no foreign matter ingress under the terminal cover or around the controller board. The frequency of these checks/cleanings is dependent upon on the installation environment. The compressor grommets (silent blocks) will outlast the compressor assuming proper installation (ex. correct torque on mounting hardware, correct spacers, etc.). As for oil changes, they are not necessary if the system has been properly installed. This includes good leak testing, evacuation, and charging procedures. The only time an oil change would be required is if the system develops a leak after charging. A leak would allow moisture to enter the system and trigger the formation of acids in the oil. However, this is not a maintenance function but is instead a repair function. Regarding the controller, even though there is no particular problem detected, it is always recommended to check that the electrical and mechanical connections are in good shape, and also to insure of the installation cleanliness (the heatsink and the electronic card must remain clean and dry). Electrical measurements and visual control of the controller will have to be performed. You can also refer to our application notes, datasheets and drawings that are available in our website, where you’ll find complementary information. (http://www.masterflux.com)

How the oil is managed?

Oil is charged into the discharge port.

Oil is transported back to the compressor by the refrigerant flow.

Is a mounting kit mandatory for the compressor use?

Grommets and sleeves are the desired mounting configuration. However, the compressor can be rigid mounted provided the plumbing consists entirely of flexible lines. However, if using rigid mounting for the compressor, the compressor vibration will be transferred through the mounting plate as opposed to be being diffused by the grommets. We do not recommend mounting any compressor without grommets due to the transfer of vibration to the mounting surface.

What is the SIERRA controller ON/OFF limit?

If the compressor is running and the voltage decreases, the compressor continues running 1600RPM as long as 0.6V. If the compressor is stopped, it will start again at 0.8V

Can a larger harness cable be used for the SIERRA compressors?

Larger harness can be used; however, keep in mind that with the additional cable length, there is a possibility of voltage drop over the extended distance.

Can a Full Speed Jumper be used with every SIERRA compressor?

We have the following jumpers available to run 12/24V & 24/48V compressors at full speed

• 040F0253 - 12/24V
• 040F0222 – 24/48V

Can a compressor be always used at full speed?

There is no mechanical concern with running the compressor continuously at full speed. The mechanism has been validated accordingly.

What is the material used on the SIERRA compressor terminal?

The rubber that is used is UL rated for 150°C (302°F).

Material

What is the SIERRA Cable material?

The material of the controller power wires are - Cross Linked Polyethylene (XLPE)

Insulated Appliance Wire, UL 3321, 150C, 600V, 10AWG

Are the SIERRA products IP rated?

We do not claim any ingress protection on our components.

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CASCADE

What is the difference between CASCADE controller 030F0137 & 030F0175?

The controllers are identical except for the heatsinks. The flat heatsink will require more airflow on it to transfer heat from the controller circuitry but will fit into a smaller work envelope (On the 030F0175, the finned heatsink has been removed, thereby reducing the surface area and the heat transfer capability.)

What is the CASCADE Controller under voltage resistor?

Resistor "R2" can be used if you would want a different under voltage trip limit. You can find the corresponding chart in the controller datasheet.

What is the benefit of using a fuse for CASCADE application?

A fuse is recommended to limit the initial in-rush current when power is first applied to the controller. At this moment, the controller on-board capacitors are being charged and a current spike can result.

Are the CASCADE controllers IP rated?

We have not done any IP evaluation for the CASCADE controllers so, technically, they are IPXX. However, the construction of the controller and enclosure prevent minor splashes from the top (similar to IPX1). There are vent slots on the bottom of the enclosure which would allow ingress.

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MESA/ATLAS

What is the SIERRA/MESA/ATLAS compressors maximal Inclination allowed?

The MESA and ATLAS compressors are allowed a maximum tilt of 30° for continuous operation, same as the SIERRAs. These are expected to be used in mobile applications, so the mechanisms have been optimized to allow for increased inclination vs. stationary compressors. The compressor can only be mounted such that the terminal is pointing upwards.

How do you control the speed for MESA compressors?

All the DCV MESA compressors can utilize a fixed resistor for speed command. The AC input voltage controller speed command method is input only at frequency, unlike the DC voltage controller. Because the Photo Coupler is applied for insulation from AC voltage external signal input, the speed instruction cannot be received with the external resistance connection.

What is the maximum ambient temperature allowed for an ATLAS compressor?

Compressor has been reliability tested to max 54°C (129°F) ambient. Most important consideration is maintaining compressor discharge and shell temps below 115°C (239°F). This can be accomplished with active cooling. Controller thermal shut-off occurs when module temp reaches 100°C (212°F). This condition can also be mitigated with active cooling.

What is the MESA compressor noise level?

In ASHRAE HBP conditions, at 3480 rpm, rated noise level:

• MESA .085 in^3 = <43 dBA
• MESA .146 in^3 = <42 dBA
• ATLAS .444 in^3 = <55 dBA

Please contact your Masterflux representative for answers to any of your questions