BOMA-Instrumentation & Controls Questions and Answers Graded A+

BOMA-Instrumentation & Controls Questions and Answers Graded A+ A submaster controller resets the set point of the master controller. False Normally open refers to a controlled device that opens when no operating force is applied. True A P.E. Switch is used to change an electrical signal to a pneumatic output. False Moisture and dirt are detrimental to the operation of pneumatic control systems. True A static pressure regulator senses the pressure in the plenum the regulator controls. The sensor that indicates this pressure to this regulator is called a_____? Static tip The intensity of a force applied to a confined liquid or gas is transmitted equally in all directions throughout the fluid in the form of fluid pressure. This statement is _____? Pascals Law The greater the applied pressure on cylinder piston or the larger the cylinder piston area, the greater the mechanical output force? True A combination starter is a switch for disconnecting and a starter mounted and one enclosure. True Full load amperage of the motor is the same as starting current. False A motor control circuit that is designed so that it must be restarted by pushing a start button after a power interruption is a _____. 3 wire control To reverse the direction of rotation of a 3 phase motor, you _____? Interchange the connection of the motor You have a normally closed steam humidifier valve. What action would the hugrostat/humidistat be? Reverse action Sensitivity: The PSI change in the control branch air line pressure for each degree of temperature change felt by the sensing elements. Static Pressure: the outward push of air against the walls of a duct or plenum. Accuracy: An instrument's ability to indicate or record the actual value of a measured quantity. Direct Acting: The action of a controller that increases its branch line pressure as the controlled variable increases. Reverse Acting: The action of a control that decreases its branch line pressure as the controlled variable increases Deviation: Departure of the control point from the set point of the amount of that departure. Dew Point: The temperature at which dew forms or condensation or vapor occurs. Span: The temperature range through which the master operates or the submaster is readjusted. Relative Humidity: The ratio expressed as a percentage of the amount of water vapor actually in the air, to the total amount present during saturation at the same temperature Psychrometer: Instrument used to determine dew point and relative humidity. Consisting of a dry bulb and wet bulb thermometer. What is the control action of the thermostat? ? If the hot water control valve was N/O instead of N/C what would the control action be? ? PS1 is what type of switch? Electric pressure switch Contactor coil 1 pulls in an electric strip heater on a cold air duct to a room. The pneumatic room thermostat operates PS1. The thermostat action is what control action? Reverse If we lost control power in the system above, the room temperature would _____? Fall/decrease in temperature In this system, if we lost control branch pressure to PS1, the room temperature would _____? Fall/decrease in temperature. The transformer would be of what type? Step down The thermostat pictured above is best described as