MAHLE RTI RHS730 User Manual Rev A

OPERATION & MAINTENANCE MANUAL

RHS730

Refrigerant Handling Station

RTI Technologies, Inc.

4075 East Market Street
P.O. Box 3099
York, Pennsylvania USA 17402
717-840-0678 (Ext. 259)
Web: www.rtitech.com
E-mail: [e-mail]

Manual P/N 035-81031-00 (Rev A)

Two Modes of Operation

The RHS730 can be used to perform semi-automatic
procedures or run in a fully automatic mode.

The following Table of Contents will direct you to the
proper sections for detailed operating instructions.

TABLE OF CONTENTS - RHS730

Before Using the RHS730 ...................... 2

Safety Precautions............................ 2

How the RHS730 Operates ..................... 3

Setup ...................................... 4

Semi-Automatic Procedures

Fill Charge Cylinder ........................... 5

Recycle .................................... 6

Drain Recovered Oil........................... 7

Manual Air Purge ............................. 7

Deep Vacuum ............................... 8

Charge ..................................... 9

Fully Automatic Procedure

Automatic...................................10

Programming & Maintenance

Access Stored Data ...........................13

Set Over Charge Amount .......................14

Calibrate Weight Scale.........................15

Scheduled Maintenance ........................16

Filter Maintenance ............................16

Change Filters ...............................16

Parts Identification ............................17

Solenoid & Contactor Identification ...............19

Technical Support 800-468-2321

BEFORE USING THE RHS730

Check for any shipping damage. Place a claim with carrier if damage is discovered. DO NOT USE A DAMAGED UNIT.
These general instructions describe normal operation and maintenance situations encountered with the RHS730. Failure

to read and comply with these instructions or any one of the limitations noted herein can result in serious injury and/or
property damage.

A few minutes spent reading these instructions can make an operator aware of dangerous practices to avoid and
precautions to take for his own safety and the safety of others. The instructions should not be interpreted to anticipate every
possible contingency.

The RHS730 should not be operated or serviced by any person who has not read all the contents of this manual.
It is the responsibility of the owner/user to operate the RHS730 in accordance with all specifications and laws which may

apply.
A regular schedule of inspection of the RHS730 should be established and records maintained with special attention given

to Hoses, Vacuum Pump Oil Level and Filters.

SAFETY PRECAUTIONS

Recycle and Charge only the refrigerant for which the machine is configured.
Wear safety glasses and protective gloves. Refrigerant has a very low boiling point and can cause frostbite.
Follow the RHS730 operating procedures sequentially to avoid prematurely disconnecting hoses or opening valves which

may release refrigerant to the atmosphere.
Do not expose the RHS730 to moisture or operate in wet areas.
Use the RHS730 in locations with mechanical ventilation that provides at least four air changes per hour.
Hoses used with the RHS730 must have shutoff devices within 12 inches (30 centimeters) of the connection point to the

A/C System to minimize the introduction of Non-Condensable Gas (Air) into the RHS730 and the release of refrigerant
when being connected or disconnected.

Disconnect power before performing any maintenance or service on the RHS730.
Connect the RHS730 to a properly grounded receptacle. Do not over load the circuit (20 amp minimum).
Avoid using an extension cord with the RHS730. If necessary, use a good condition three wire, grounded, #14 AWG (2.0

2

) or larger extension cord of the shortest possible length (maximum 25 ft. - 8 m).

mm
Do not connect the RHS730 to the liquid side of any A/C System with a capacity greater than 4 lbs (1.8 Kg.) Refrigerant

in A/C Systems having larger capacities must be recycled from the vapor side only.
Never connect the Red or Blue Hose of the RHS730 to the Liquid Port of a Cylinder of Refrigerant to fill the Charge

Cylinder. Doing so may cause the Compressor to fail and void the warranty.
Avoid breathing refrigerant or lubricant vapor or mist. Exposure may irritate eyes, nose and throat. If accidental system

discharge occurs, ventilate work area before continuing.
Additional health and safety information may be obtained from refrigerant and lubricant manufacturers.

SPECIAL CONSIDERATIONS WITH R134a

R134a has been shown to be nonflammable at ambient temperature and atmospheric pressure. However, tests under
controlled conditions have indicated that at pressures above atmospheric and with air concentrations greater than 60
percent by volume, R134a can form combustible mixtures.

While it is recognized that an ignition source is also required for combustion to occur, the presence of combustible mixtures
is a potentially dangerous situation and should be avoided.

Under no circumstances should any equipment be pressure tested or leak tested with air and R134a mixtures. Do not use
compressed air (shop air) for leak detection in R134a systems.

Page 2

HOW THE RHS730 OPERATES

The RHS730 is microprocessor controlled with a menu-driven user interface. All functions are performed by entering a few
simple key strokes and following the prompts on the display. The on-board charge cylinder is mounted on a load cell. The
weight of refrigerant in the charge cylinder is electronically displayed.

The RHS730 has a Fill Cylinder feature which allows refrigerant to be transferred directly into the charge cylinder without
going through the normal Recycle mode. This feature allows the RHS730 charge cylinder to be re-filled directly from a
cylinder of new refrigerant. The process automatically stops at approximately 20 lbs (9 kg).

The RHS730 recycles refrigerant in a true single-pass through the filters and stores the refrigerant in the charge cylinder
where it’s immediately available for use. This process automatically stops at 24 lbs (11 Kg) or when a 15 In-Hg (-0.5 Bar)
vacuum is sensed in the A/C system.

The RHS730 pauses for a minimum factory-set default of two minutes for out gassing and cold refrigerant to raise the
pressure back up to 3 psig (0.2 Bar) at which time the recycle process will start again and reset the Recycle Hold Timer.
When the pressure does not rise to reset the timer during the two minute pause, the display will indicate that the process
is complete. The Recycle Hold Timer can be changed every time a Recycle procedure is run.

Longer recycle hold times should be selected on colder days or when servicing an A/C system with a large liquid capacity.
Increasing this value may increase total time to recycle while decreasing the time may result in an incomplete recycling
of refrigerant from the A/C system.

Refer to the table below for guidelines on setting the Recycle Hold Timer. The value entered is stored in the memory of
the RHS730 and becomes the default value each time it is set.

0

Temperature Less than 50

Recycle Hold Time 10 minutes 5 minutes 2 minutes

F (100 C) 500 F (100 C) to 800 F (26.50 C) Greater than 800 F (26.50 C)

Non-condensable gases (air) are vented automatically during the recycle process.
The amount of refrigerant recycled is displayed at the end of the procedure. This value is added to the total amount

recycled and is stored in the memory of the RHS730.
A 7 CFM vacuum pump draws on both the high and low hoses, ensuring c omplete evacuation of the A/C system. The

amount of time that the vacuum pump has been programmed to run will count down on the display. The value entered is
stored in the memory of the RHS730 and becomes the default value each time it is set.

The low pressure gauge can be monitored to see a rise in A/C system pressure. When programmed to do so, the RHS730
will pause and start a count up timer indicating how long the vacuum pump has been off, thus allowing the operator to
determine if a vacuum leak is present based on increasing pressure over time. A rapid rise in pressure indicates the
presence of a large leak that should be repaired. A slow rise in pressure may simply indicate that a longer recycle hold time
or vacuum time value should have been entered.

A relatively constant vacuum reading over a long period of time (less than 2 In-Hg [0.05 Bar] rise over ten minutes) is the
most accurate way to check for vacuum leaks.

The RHS730 can also be programmed to pause to allow oil to be added to the A/C system after vacuuming and prior to
charging.

Charging is done from the on board charge cylinder. An integrated heater automatically engages whenever charging
occurs. The A/C capacity is entered on the Keypad. The value entered is stored in the memory of the RHS730 and
becomes the default value each time it is set. As refrigerant leaves the RHS730, the display will show an increasing weight
up to the programmed charge amount plus a factory-set one ounce (0.03 Kg) over charge amount necessary for
compensation of refrigerant loss in the hoses.

The over charge amount can be changed to accommodate different operating conditions. The amount of refrigerant
charged is added to the total amount charged and stored in the memory of the RHS730.

The high side red hose can be connected to the low side port o f the RHS730 for charging to the low side of
vehicles with only a low side port. Follow the vehicle manufacturer’s charging procedure when charging to
the low side to avoid damaging the A/C system compressor.

Page 3

SETUP

New

Refrigerant

Anti-Blowback

Valve

To Fill Port

Page 4

WEIGHT= XX.X LB

AUTOMATIC

?

>>>>

WEIGHT= XX.X LB

FILL CYLINDER

?

FILL CHARGE CYLINDER

1. Connect a cylinder of new refrigerant to the Fill Port on the rear of the

5

RHS730 as shown on Page 4. Anti-blowb ack Valve must connect to
the RHS730. Turn the cylinder up-side-down. Turn Main Power Switch on.

The display will show WEIGHT= XX.X LB AUTOMATIC?

2. Press the

5

CYLINDER?

> key four times to display WEIGHT= XX.X LB FILL

5.

5.

ENTER

START

?

ENTER

WEIGHT= XX.X LB

COMPRESSOR ON

FILL COMPLETE

FILLED= XX.X LB

ENTER

*

HIGH PRESSURE

SEE MANUAL

3. Press the ENTER key. The display will read START?

4. Open the valve on the cylinder of new refrigerant.

5. Press the ENTER key to start filling the RHS730.

5

6. Close the valve on the refrigerant cylinder.

7. Press the ENTER key to return to the Main Menu.

5

The Display will read WEIGHT= XX.X LB COMPRESSOR ON.
When the weight is approximately 20 lbs (9 kg) the RHS730 will turn
OFF, the display will read FILL COMPLETE FILLED=XX.X LB
(the amount of refrigerant removed from the cylinder). The Attention
Light will turn on.

The RESET button on the keypad can be pressed at any time to stop
the Fill Cylinder procedure prior to it filling and shutting off
automatically.

This procedure may be slow or fail to work if the internal
charge cylinder pressure is higher than the pressure in the
cylinder of new refrigerant. Check and purge air if necessary
(See Page 7).

Also, try putting a heat belt on the new refrigerant cylinder.

5.

5

**

CYLINDER FULL

GO TO CHARGE

5

* While filling the charge cylinder, this screen will display periodically

concurrent with the Attention Light turning on. This is normal and
nothing to be concerned about. The screen will return to normal after
a few seconds.

** This screen will display if the charge cylinder fills to capacity,

approximately 24 lbs (11 Kg). If this occurs, the weight can be lowered
using the Charge procedure on Page 9. This must be done before the
RHS730 can be used to recycle more refrigerant. Press the ENTER
key to return to the Main Menu.

Notes:

It may be desirable to skip this procedure for large capacity or multiple A/C systems where recharge will not be
done between successive recycling procedures.

The RHS730 uses 22 lbs (10 Kg) of refrigerant when filling the first time. If the cyli nder of new refrigerant is
emptied, the RHS730 will appear to stop filling (the weight displayed will stop increasing) and w ill stay in this
condition until the RESET key is pressed.

The RHS730 will use 1.1 Lb (0.5 Kg) more refrigerant than the displayed value the very first time it is used or after
performing a Calibration Procedure in order to prime the internal components.

The RHS730 Charge Cylinder can also be filled from the GAS or VAPOR side of a cylinder by following the Recycle
procedure on Page 6.

The yellow hose can be disconnected from the Fill Port on the rear of the RHS730 and reconnected to either the
Blue (Low side) or Red (High Side) hose connection port on the side of the RHS730 to allow recycling any
refrigerant remaining in the yellow hose using the Recycle procedure on Page 6.

Page 5