Today I had a chance to dig around inside a large Crestron DM installation which was performed here just a couple of years ago. The department owners/users have had significant problems with the installation ever since the job was completed. Unfortunately, due to politics, my own department and I were never consulted and we were unaware of the project’s scope until after the installers were on site. The installation was performed by a large and well-known design-build firm. The owners/users are generally happy, but there are random failures and at the moment all audio has died, prompting the request for my consult. The owners were never provided as-built drawings. This is a full DM matrix with support for video conferencing and multiple displays.
I spy some significant installation errors and poor practices. What do you think? The system is in two parts: a lecturer’s console with rack, and a full-size distribution rack in a nearby closet.
The console casework is nice, but the rack is barely large enough to support all of the hardware needed for the front-end of the system. The desk is height-adjustable, electrically; but is not used since stuff stops working whenever the desk is raised (see below).
It wasn’t until after the system was in operation that the users discovered there was not appropriate horizontal real estate for laptop users. DOH!
The console rack is 15-RU and four of the spaces are taken up by horizontal power strips. There is room in the rear of the rack for vertical strips which could have possibly allowed tidier cable dressing between hardware and a traditional cable dump at the bottom.
This is a mess.
There are a number of jumper cables which are too long, so they are coiled up and hung from self-adhesive tabs(!) Several of the tabs have failed (they all do, in time), causing the weight of the cables to put stress on the connectors and cause random disconnects–particularly any wretched HDMI connectors.
Here is a look up inside of the rack.
Standard plastic cable ties are used on all cables including category and DM.
It is not so obvious in these images, but power cables are often seen cable-tied to signal cables–very poor practice and definitely contrary to the contract specs. Nobody called them on it.
Under the desk proper, things could have been dressed better, and cables with generous service loops bundled more securely to allow for the desk height adjustment without stretching cables and connectors like a bow string. I can see how raising the desk will cause failure.
The main distribution rack is located in a very small closet behind the whiteboards:
The rack has to be on casters to rotate for access in this tiny space. In this image it is turned for access to the rear of the rack.
I seem to recall the wall-mounted air conditioner was added after-the-fact to mitigate overheating.
At first view the in-rack wiring looks quite tidy!
Let’s look more closely.
It appears that power cables are on the left, and signal cables are on the right. Excellent.
Hmmm. I don’t see any Velcro straps used on the category cables yet. Are those cable ties really as tight as they appear?
Here again, power cables are tied alongside the DM, audio and LAN cables. No Velcro ties.
Shielded, twisted-pair cables are nicely terminated and labeled, but no cable ties were used to secure the cable to the connector.
This is beneath the Ethernet switch. Category cable cinched down with cable ties alongside the power cables.
Along the side of the rack, there are bundles of power and signal cables kinked together:
I will have a look around again later. The owners have asked the installers to return and repair the intermittent problems, as well as to provide the as-built drawings the original contract required. The system is “out of warranty” so time-and-materials charges apply. What do you think? Would you ever use these installers?