Manual

Installation-Wiring
Installation - Wiring, Chapter 3
26 WATLOW Series 1500 User's Manual
Chapter 3
How to Install and Wire the 1500
This chapter tells you how to install and wire the Series 1500. There are also some
suggestions for sensor installation. Also, be sure to look at the noise reduction
guidelines before making your panel cutout.
Sensor Installation Guidelines
Temp-RH
In this 1500 configuration, a dry bulb RTD measures temperature on Channel 1. A
wet bulb RTD, in combination with the dry bulb RTD, senses relative humidity on
Channel 2. The 1500 calculates the temperature difference between the two bulbs to
determine percent relative humidity.
Temp-Temp
For Temp-Temp RTD operation, each dry bulb RTD senses temperature for its
channel.
RTDs
The RTDs for the Series 1500 are customer-supplied items. They may be Gordon
Part #S001-0133-0000, which is a wire-wound RTD inside a sealed, 18% Nickel-
Silver sheath, made for fast temperature response. The detector element is platinum
wire 100Ω at 0°C with a temperature coefficient of 0.003916Ω/Ω/°C. The sheath is
0.1875 in. (5 mm) diameter, 2.75 in. (70 mm) long. The three wire leads are 48 in.
(1219 mm) long and teflon insulated.
Contact Gordon at:
5710 Kenosha St., Box 500
Richmond, IL 60071
Phone: [phone]
Excessive lead length in a two-wire RTD sensor can create indication errors. To
combat this, use a three wire sensor in long lead applications.
RTD - The Dry Bulb Installation
We suggest you mount the dry bulb RTD at a location in your process or system
where it reads an average temperature. Air flow past this sensor should be moder-
ate. The sensor should be thermally insulated from the sensor mounting.
RTD - The Wet Bulb Installation
One way to prepare the RTD wet bulb sensor for reading relative humidity on Chan-
nel 2 is to slip a cotton wick over the sensor sheath, Watlow Part # 0830-0111-0000
or an equivalent. Put one end of the wick in water. Some systems use a small
trough of water with a float valve to replenish the evaporating liquid.