We
have had some blistering hot and humid days, that hit all of a sudden, and have
gotten a lot of calls from equipment failure due to hot weather, no
ventilation, controller failure, relay failure, door operator failure, motor
failure, etc. Our elevator mechanics have been chasing calls since the heatwave
began. The original post was from 2017,
reposted in 2018, 2021, 2022 and now as we approach 100 degrees in 2024.
This
summer we have seen more frequent failure of solid state boards and equipment
that has been exposed to extreme heat and cold.
Building owners frequently ask “why is this occurring”. I always like to give some research and
background when explaining to building owners, so they can be better educated,
and came across a great article from which I have taken some of the high
points. When reading this, be aware that
most issues with machine room environments will result in a shut down or needing
a replacement board. However incorrect machine temperatures can also cause
malfunctions which could result in an elevator operating in an unsafe
condition.
The
subject of the operation of an elevator in an elevated high ambient machine
room temperature is one of concern for elevator manufacturers, code writes,
enforcing authorities, building owners and operators, elevator consultants and
fire safety personnel. Today’s
solid-state design elevator control systems are able to maintain rated
performance over a wide range of normal design operating temperatures but are
vulnerable to elevated temperature conditions.
NEII
Vertical Transportation Standard calls for machine room/or machinery spaced
temperature to be between 55 and 80 degrees Fahrenheit.
NEMA
has established a maximum temperature limit of 104 degrees Fahrenheit.
National
Electrical Code[NEC] has published 86 degrees Fahrenheit as the standard
ambient for conductor ampacity ratings.
Computer
manufacturers recommend an ambient temperature of 60 to 90 degrees
Fahrenheit. Your elevator's
microprocessor controller is a computer.
The
effects on solid state components due to temperature may be classified in two
areas; operating[reliability] and failure[life]. The manufacturer's recommendation for ambient
temperature will allow the devices to operate in a repeatable and predictable fashion. Temperatures above or below the recommended
temperature will decrease the life of the solid-state system.
Hydraulic
fluid - Heat will affect your hydraulic fluid as well as your electronic
components. Hotter oil means thinner
oil, means different leveling, means potential for unlevel conditions and trip
and falls.
Please
note - Elevator controller temperatures are 10 to 15 degrees warmer inside the
controller with the cover on. If an elevator machine room is 105 degrees, the
temperature when you open the door to the controller could be over 120 degrees.
Causes
of machine room over temperature
1. Failure of machine room ventilation or no
ventilation
2. Failure of cabinet ventilation system – air
condition or fan
3. Increase in the elevator duty cycle beyond
design criteria
4. Sustained operation at low AC input levels
The
recommendation of machine room temperature control comes from a few different
areas
1. Normal temperature in room – in Chicago we
have hot summers and cold winters
2. Amount of heat released from the elevator
equipment in the machine room – depends on the equipment you have and amount of
traffic in the building
3. Amount of ventilation and/or air
conditioning/heating provided in machine room.
Take
away – Be aware of the machine room environment and make preparations i.e. air
conditioning[best case] or ventilation in summer and heating in the winter.
Reference
– “High temperature operation of elevators” by Nick Marchitto
If
you have any questions or would like additional information feel free to
contact me at CraigZ@colleyelevator.com or 630-766-7230 ext. 107.
Also
check us out on Instagram @Colleyelevator see what we have been up to.