Like all compressors made by Andover Protection Systems, LLC, APS’ Division/Zone 1 compressors are all hermetically sealed for two reasons:

  • To protect the environment from any risk of sparks escaping from the motors and other inner workings.
  • To protect the compressors from the environment—corrosion, dust, water and other potentially-harmful elements.

In addition, to make them safe for frequent, or even constant, presence of hazardous-gases or dusts in potentially explosive concentrations, APS’ Division/Zone 1 compressors are further protected by enclosing the electrical connections inside in an explosion-proof enclosure (virtually the same as a flame-proof enclosure) to assure that:

  • Hazardous gases and dusts cannot reach the electrical connections
  • If harmful gases or dusts manage to enter the housing and explode (for instance, when someone opens the enclosure in the hazardous environment and traps the explosive gas or dust inside), the enclosure will contain the explosion and will not let it escape into the atmosphere

Access for wiring is gained through the end of the enclosure by removing the plug.  Normally four inches (10 cm) in diameter, APS designs most enclosures large enough to allow a person to insert their hand to wire up the connections.  Almost all sizes of APS compressors from the smallest fractional-horsepower models to the largest—about 30 horsepower—offer the easy access for wiring.

The wires enter the enclosure through a male-threaded nipple to which the installer can attach any appropriate connecting and sealing device.  In most cases, the customer can specify the direction toward which they wants the nipple to extend (12 o’clock, 4 o’clock, and the like) to make connecting the wires, seals and conduit as easy as possible.

All APS compressors are available in many Division/Zone 1 configurations

APS offers more than 1000 models, ALL recognized by Underwriters Laboratories, Inc. (UL) as safe for use in hazardous locations.

Using components that are already approved by an NRTL (Nationally Recognized Testing Laboratory approved by OSHA) makes it easier faster and less-expensive to obtain third-party inspectors’ approvals and listings from NRTLs (such as UL, ETL, and CSA) and from local governmental inspectors.   NOTE:  Open compressors are not tested and recognized by UL for use in hazardous locations.

APS Compressor Characteristics:

Easy, safe wiring

Adaptable design to fit users’ configuration

Many electrical configurations

In some applications, APS compressors can eliminate the need for a separate NEMA 7 boxes because the enclosures have enough space to house thermostats or other controls)

Compatible with most refrigerants (HFCs, HCFCs, CFCs, CO2, propane and isobutane)

Models for low, medium and high-temperature applications

Installed in dozens of countries around the world

Make construction and installation of air-conditioning and refrigerating systems faster, easier and less expensive while increasing the flexibility of the designs.  (In fact, in many cases the APS compressors are so compact that the OEM can use essentially the same design as it would for ordinary (non-hazardous) versions of their chiller or other product.)

Why use APS compressors?

No other compressors are tested and expressly recognized by Underwriters Laboratories (UL) as safe for use in either Division/Zone 1 or Division/Zone 2 locations in any class or group.

APS does not change the operation or performance of the compressors, just makes them safer.

When you assemble a complete product, APS’ proven designs and UL’s recognitions assure that the compressor is safe for the indicated environments and therefore that part of the unit will not have to be tested independently to verify its safety, thereby reducing the costs of UL listing of your products.

The threaded plug on the 3 1 /2 ” (8.9 cm) ID enclosure makes wiring, and even rewiring, easy because a technician can fit their hand inside to work on the wiring.

Protect electrical connections in corrosive, wet, and other harsh environments

APS protects all its compressors with resistant coatings to assure long life in corrosive environments.

APS offers scroll and reciprocating compressors with POE, mineral and other types of oils in capacities from 1/20 Horsepower to 30 HP and for low, medium and high-temperature applications.  To assure that we provide you the best model for your purposes, please complete and return the data form:  Click Here

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