On Oct 13, 5:37*am, klem kedidelhopper
wrote:
On Oct 12, 10:48*am, nesesu wrote:





On Oct 12, 6:12*am, klem kedidelhopper
wrote:

I have this unit which I installed many years ago in a new fast food
business. The restaurant failed shortly after it was installed and I
got the equipment back. So in essence it is like brand new.and was
operational when it was removed from service.

The unit is a self contained box with loop sense wires and isolated
spdt relay wires. It operates from 120V. The loop was buried in the
driveway and so I was unable to retrieve that part of the system.

Installation was rather simple. Unfortunately I can't find the
installation instructions however I do recall that we had to cut the
asphalt driveway and bury a loop of AWG. 14 cable. The loop would
sense a large mass of metal over it such as a car, (as opposed *to a
non metallic mass), at a drive through and operate a form C relay. I
would like to set this unit up in my own driveway now however the
problem is I don't remember the configuration of the loop, IE how many
turns there were in the loop or its diameter. Actually I think that we
buried it down 8 inches or so and that it was rectangular shaped but
I'm just not sure.

There is no longer a listing for Detector systems however the strange
thing is the number 917-1 does come up as some kind of driveway sensor
but I can't seem to find any information on it.

I would think that this type of unit must be similar to those that are
used at intersections for traffic light control but I'm not sure how
to find that information.

Does anyone have any experience with this type of sensor who can
advise me as to the sense loop characteristics? *Thanks for any
assistance, Lenny

A few thoughts on these sensors. Generally, the loop is non critical
and the unit automatically compensates for variation. The loop is
somewhat standardized since one does not dig up the road to change the
loop if the detector unit needs replacing. I seem to recall that the
loop is typically about 4' x 8' and about 2 or three turns. One could
easily tape a test coil to the driveway and try it out. Usually, the
coil is buried about 3-4" into the asphalt.
Try looking up the oldest sensor info you can find [Eagle signals?]
and see what info it has on the coil.
Usually, the connections on the quality sensors is by a single 'MS'
type circular connector with 8 connections. You should be able to open
the case and trace the pinout. Connections should be: AC input [line,
neutral, ground], Output [NC, COM, NO] and LOOP.
You could also check with your local roads department's electrical
shop. Good luck!

Neil S.- Hide quoted text -

- Show quoted text -

Hi Neil
I made a coil in the configuration you described out of 14AWG. wire.
The coil is 4 turns of wire with a 4 X 8 rectangular shape. The
perimeter is 96" approximately. I just realized that this is a larger
perimeter than you suggested so I wonder if that might cause a
stability problem such as I'm having? The funny thing is with this
coil the control unit will sometimes detect the vehicle every time on
the approach, (within 2 feet of the car even before the car passes
over it. At other times there is no detection at all. I tried the
different modes, pulse, 2 second delay, presence, *and messed with the
sensitivity. So I'm wondering if I need more or less turns or maybe a
different loop size.
I could be wrong because this was a long time ago but the driveway may
have been about 8 feet wide. The cuts we made for the coil may have
been much narrower than this coil. Those cuts could have been 8 feet
by say 4 or 5 inches or so. Do you think that could have been
possible.? Would configuration and size cause a reliability problem
such as I'm having? This is so frustrating. I know that the system
worked well at the time. I just can't remember exactly what we did.
Thanks for any further input. Lenny- Hide quoted text -

- Show quoted text -

Lenny, I am a bit puzzled by your coil description. You say it is 4 x
8 and 4 turns, but has a perimiter of 96". Since 96" is only 8', I
would think that the coil you made would have a perimiter of 288". Try
and reduce the coil to 3 turns, but don't cut the wire off. The leads
from the unit to the coil should be twisted together or you can get
some funny results due to stray pick-up. Normally, the unit should not
pick up the car until it is on top of the coil--it sounds like you
have too much sensitivity--which is why I suggest reducing the coil
turns. I have also never seen more than 2 or 3 turn coils, but that
does not mean much.
I cannot say I have seen any really narrow coils like you describe,
but some on driveways are like 4' x 3' and the newer ones on the
highway are about a 4' circle [neat machine that cuts the circular
slot in the road surface]. Size and configuration are THE important
thing in these coils, so it needs to be right for that unit. It is
really not much different that getting a radio back loop antenna to
track the tuning dial--a fair bit of cut-and- try.

Neil