VARIABLE FREQUENCY DRIVES. The drive package as specified herein and defined on the drive schedule shall be enclosed in a UL Type enclosure (enclosures with only NEMA ratings are not acceptable), completely assembled and tested by the manufacturer to ISO9001 standards. The drive shall provide full rated output from a line of +10% to -15% of nominal voltage. The drive shall continue to operate without faulting from a line of +30% to -35% of nominal voltage. Drives shall be capable of continuous full load operation under the following environmental operating conditions: Ambient temperature -15 to 40° C (5 to 104° F). Altitude 0 to 1000 m (0 to 3,300 ft) above sea level. Humidity 5 to 95%, non-condensing. All drives shall utilize the same Advanced Control Panel (keypad) user interface. Plain English text The display shall be in complete English words for programming and fault diagnostics (alpha-numeric codes are not acceptable). Safety interlock and run permissive status shall be displayed using predetermined application specific nomenclature, such as: Damper end switch, smoke alarm, vibration trip, and overpressure. Safety interlock, run permissive, and external fault status shall have the option of additional customized project specific terms, such as: AHU-1 End Switch, Office Smoke Alarm, CT-2 Vibration. The control panel shall include at minimum the followings controls: Four navigation keys (Up, Down, Left, Right) and two soft keys to simplify operation and programming. Hand-Off-Auto selections and manual speed control without having to navigate to a parameter. Fault Reset and Help keys. The Help key shall include assistance for programming and troubleshooting. Multiple Home View screens shall be capable of displaying up to 21 points of information. Customizable modules shall include bar charts, graphs, meters, and data lists. Displays shall provide real time graphical trending of output power, frequency, and current within selectable intervals of 15/30/60 minutes and 24 hours. The control panel shall display the following items on a single screen; output frequency, output current, reference signal, drive name, time, and operating mode (Hand vs Auto, Run vs Stop). Bi-color (red/green) status LED shall be included. Drive (equipment) name shall be customizable. There shall be a built-in time clock in the control panel. The clock shall have a battery backup with 10 years minimum life span. Daylight savings time shall be selectable. I/O Summary display with a single screen shall indica...
VARIABLE FREQUENCY DRIVES. 1. Should there be a requirement of MV VFDs, the Contractor shall ensure MV VFDs are procured in accordance with 240-50237146 requirements. Technical Schedules A and B (New MV VFD Technical Schedule AB Template 240-132875114) shall be provided to Employer for design acceptance.
VARIABLE FREQUENCY DRIVES. Variable frequency drives were installed on hot water pumps at Xxxxxxxx Regional Middle School, Xxxxxxx X. Xxxxxx, and Pittston Consolidated School. Energy savings are achieved by reducing the speed of the motor to match the buildings heating load using pressure sensors instead of running at full speed all of the time. The following section details the VFD operation at each building. Due to server issues trending was unavailable from July 1, 2017 through October 6, 2017. Total savings for the VFDs equaled $1,981 in realized savings, which is $2,825 short of the guaranteed savings of $2,825 (Table 67). Table 67 – Summary of Variable Frequency Drive Energy and Cost Savings Facility Improvement Measure Electric Energy Savings (kWh/ yr) Realized Cost Savings ($) Guaranteed Cost Savings ($) Excess/ Shortfall in Savings ($) Building Automation Variable Frequency Drives 16,008 $1,981 $2,825 ($844) Xxxxxxxx Regional Middle School 2,632 $326 $1,341 ($1,015) Xxxxxxx X. Xxxxxx 8,048 $996 $894 $102 Pittston Consolidated School 5,328 $659 $591 $69 Xxxxxxxx Regional Middle School: VFDs were installed on two 7.5 HP hot water pumps (HWP-3 and HWP-4) in at the Xxxxxxxx Regional Middle School boiler room. Savings were verified by trending electric consumption of both pumps continuously throughout this annual period. Since trending was not available for the entire Annual Period the electricity consumed during the missing months was calculated using the following method.
