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 and now edited for 2022.
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.
hi
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