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Coded panels were the earliest type of central fire alarm control, and were made during the 1800s to the 1970s. A coded panel is similar in many ways to a modern conventional panel (described below), except each zone was connected to its own code wheel, which, depending on the way the panel was set up, would either do sets of four rounds of code until the initiating pull station was reset ...
Variable Speed Fire Pump Controllers were invented and released with a UL Listing for fire pump service in 2003 by Master Control Systems, Inc. [1] [2] Paragraph 10.5.5 in the 2003 edition of NFPA-20 recognized Variable Speed as an accepted method for operating the fire pump. Then in the NFPA-20 2007 edition, section 10.10 was added to clarify ...
A fire pump is a centrifugal-or positive displacement-pump that has been tested and listed by a third-party testing and listing agency, such as UL or FM Global specifically for fire service use. The main standard that governs fire pump fixed-place installations in North America is the National Fire Protection Association 's NFPA 20 Standard for ...
Many modern fire alarm pull stations are single-action and only require the user to pull down a handle to sound the alarm. Other fire alarm pull stations are dual-action, and as such require the user to perform a second task before pulling down, such as lifting or pushing in a panel on the station or breaking a glass panel with an attached hammer.
A motor control center (MCC) is an assembly to control some or all electric motors in a central location. It consists of multiple enclosed sections having a common power bus and with each section containing a combination starter, which in turn consists of motor starter , fuses or circuit breaker , and power disconnect . [ 1 ]
A control loop is the fundamental building block of control systems in general and industrial control systems in particular. It consists of the process sensor, the controller function, and the final control element (FCE) which controls the process necessary to automatically adjust the value of a measured process variable (PV) to equal the value of a desired set-point (SP).
A baby without a father. A mother who carries her son in an urn. Two teens behind bars. Nearly two years after the shooting outside a Whataburger, the families involved are still reeling.
LCR – local control room; LCV – level control valve; L/D – lay down (such as tubing or rods) LD – lay down (such as tubing or rods) LDAR – leak detection and repair; LDHI – low-dosage hydrate inhibitor; LDL – litho density log; LDS – leak detection system (pipeline monitoring) LDTEP – LDT EPT gamma ray log; LEAKL – leak ...