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HomeMy WebLinkAbout310.300 - TELMA Frictionless Braking SystemEffective Date: July 2021 Robert J. Garcia, Engineer Current Revision Date: 6/13/2023 Section 310.300 Next Revision (1) Date: 6/13/2025 Page 1 of 5 Fresno City Fire Department 300 Training and Equipment Manual SECTION 310.300 TELMA FRICTIONLESS BRAKING SYSTEMS PURPOSE The purpose of this policy is to provide the Fresno Fire Department (FFD or Department) with outlined instructions pertaining to the operation of the TELMA Frictionless Braking System (TELMA). APPLICATION The TELMA Frictionless Electromagnetic Braking System installed on 2017 and newer FFD Engines. The TELMA provides an additional braking system that works along with the service brakes providing increased safety and less wear on the braking system. OPERATIONAL POLICY The TELMA should be inspected daily per the inspection process outlined below. OPERATIONAL GUIDELINE The TELMA should be disabled by switch or in the vehicle multiplex operator control screen (VMUX) located in the apparatus cab, if being driven in icy conditions or such environments could be encountered. The TELMA interacts on the Controller Area Network (CANBus) with the Antilock Braking System (ABS) and can be used when in wet conditions such as rain. The ABS will send a signal through the CANBus before a wheel slip is going to occur and disable the TELMA from activation, preventing a skid becoming worse by TELMA activation. The manual hand control should be limited to the 1st or 2nd position if being used in a wet environment. PROCESS This section intentionally left blank. Effective Date: July 2021 Robert J. Garcia, Engineer Current Revision Date: 6/13/2023 Section 310.300 Next Revision (1) Date: 6/13/2025 Page 2 of 5 INFORMATION Operation: The TELMA provides three applications for supplementing the service breaks. The TELMA can be controlled by the brake pedal application, manual hand control, or the off-throttle control. Below are details of the types of controls and the typical application they are used for. Brake Pedal Application: This type of control is used when it is desired to have automatic application when the brake pedal is applied. It is typically used in stop-and-go type applications. For best brake life anticipate stops and apply light pressure on the brake pedal to activate the four TELMA stages progressively before the service brakes are used. The TELMA’s four stages are activated based on pressure applied to the brake pedal. Manual Hand Control: This type of control is used for mountainous applications where TELMA activation on long downgrades without applying the service brakes is desired. The apparatus descending the grade with the occasional service brake application where only two TELMA stages are needed to maintain speed. The third and fourth stages are to be used intermittently. The hand control lever is a 5-position switch mounted on the dash that operates independently of the brake pedal (Figure 1). The 5 positions are as follows: • 0- Power off • 1- 25% Power • 2- 50% Power • 3- 75% Power • 4- 100% Power (Figure 1) Effective Date: July 2021 Robert J. Garcia, Engineer Current Revision Date: 6/13/2023 Section 310.300 Next Revision (1) Date: 6/13/2025 Page 3 of 5 Off-Throttle Control: Off-throttle control allows the TELMA to be automatically activated when the driver lets off the accelerator pedal and before the brake pedal is applied. The hand control is used to select the desired power of the TELMA for off throttle control. This control is not progressive so a maximum of two stages (50%) of the TELMA is to be used in this manner. Off throttle control is combined with foot control so the remaining stages are activated by the brake pedal. Dashboard Indicator: The dashboard indicator is the driver’s main indication of the TELMA’s function. This indicator contains four separate LEDs within the display (Figure 2). Each light corresponds to one of the stages of the unit. The lights indicate that the TELMA is operating. They should never illuminate when the apparatus is stopped or when the accelerator is applied. (Figure 2) Inspection: While performing the daily inspection, the driver is to perform an inspection of the TELMA. A road test is to be performed to observe the proper function of all three braking applications and dash light function. Lights should come on when the TELMA is engaged. All TELMA dash lights should be off when apparatus is accelerating and when it comes to a complete stop. A visual inspection of the TELMA is to be performed checking for the following: • Any damage to the coils, stator, or rotors. • Condition of wiring. • Fasteners for tightness. • Any leaks. • Secureness of heat shields located near brake chambers. • Overall condition of the TELMA. Effective Date: July 2021 Robert J. Garcia, Engineer Current Revision Date: 6/13/2023 Section 310.300 Next Revision (1) Date: 6/13/2025 Page 4 of 5 Maintenance: The following maintenance of the TELMA is performed by shop personnel. If pressure washing is deemed necessary by the operator between services, a service requisition is to be completed, and the shop is to schedule a time for pressure washing (Figure 3). Effective Date: July 2021 Robert J. Garcia, Engineer Current Revision Date: 6/13/2023 Section 310.300 Next Revision (1) Date: 6/13/2025 Page 5 of 5 (Figure 3) Below is additional information: Operating Principle Telma Owners Manual Telma PowerPoint Maintenance Guides and Service Bulletins How to Videos DEFINITIONS This section intentionally left blank. CROSS REFERENCES This section intentionally left blank.