E-MAIL: [email protected]

DATE: May 10, 2000 YOUR REF.NO.:

MILNOR REF NO.: FAX NO.:

TO: Service Manager FROM: Gary Lazarre

COMPANY: MILNOR Dealers RETURN TO: Diane Schnauder, Service Dept.

NO. OF PAGES (including this one):

SUBJECT: OVERSPUN WASH MOTORS

APPLICATION: Large Open-Pocket Washer/Extractors with Isolator Style Mounting

This bulletin applies to machines utilizing an air clutch and a 2- or 4-motor drive with isolator style mounting of the shell to the frame. The typical operation of this machine would call for wash and distribution speeds using an inflated air clutch which couples the wash and drain motor to the final drive pulley.

As the machine calls for low extract, the air clutch is deflated disengaging the wash and drain motor from the higher speed extract motor group. If the clutch were to remain engaged, the E-1 motor would accelerate the low speed drive (wash and drain motor and gear reducer) to a very high speed causing damage to the wash motor and possibly even the drain motor.

We have evidence that shows overspun wash motors as a result of leaking clutch valves. We believe that a likely scenario is as follows:

The clutch valve is turned off at the onset of extract. The quick release - mounted on the gear reducer - releases and exhausts the air clutch tire. Then at some point in low extract or even high extract, the air clutch re-inflates (very slowly through the bad seat in the valve).

The result is the acceleration of the low speed drive and the destruction of the cooling fins on the wash motor.
These cannot withstand the centrifugal force generated by the high speed of the motor. The motor could indeed be accelerated up to 10,000 rpm or more as the clutch engages. Obviously, these motors are not made to withstand such a high speed.

The first thing to do is to check the air clutch pilot valve. If there is the slightest amount of air leaking past the seat, then the valve should be rebuilt or replaced. The valve part number is 96TBC3BA37. Additionally, we have installed a normally open by-pass valve on the clutch air circuit. Our intention was to relieve the air pressure in the air clutch allowing a small leak to dissipate to atmosphere rather than inflate the clutch.

The health of your clutch valve is imperative to proper machine operation. The cost of a wash motor is extremely high compared to the repair cost of the air clutch valve. We are happy to provide the retrofit kit and instructions to install the normally opened by-pass valve at no charge for parts to the end user. (Order kit KDACVNORNC)

A recent report from the field revealed that a wash motor was replaced due to over spinning and when the new motor was received and put in place, that motor also overspun on the first extract cycle.

Be sure that the expense is extreme!

We ask you to give this bulletin wide distribution through your technical staff and would further recommend that the clutch air valve be put on a monthly preventive maintenance check list to insure that no minor leak exists.

If you have any questions, please call MILNOR Tech Support at 504-467-9591, ext.75, or fax 504-469-9777 or E-mail [email protected].

Best regards,

PELLERIN MILNOR CORPORATION
Gary Lazarre
Gary L. Lazarre
Manager
Customer Service