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Series-500-LevelConfiguration
Durable Insertion Level Control for Tanks - Adjustable, Multi-Mount
- Adjustable insertion design mounts directly into tanks for flexible installation
- Multi-mount options support thread or flange connections for high-pressure or high-temperature tanks
- Weatherproof NEMA 4X/4 (IP65) enclosure for outdoor or harsh-environment service
- Reliable SPDT snap-action switch; accommodates liquids down to specific gravity ~0.55 for broad compatibility
Product Overview
- Series ID Series-500-Level
Supported Applications
The Dwyer Series 500 provides durable insertion level control for tanks, designed as side-mount liquid level controls. The series is documented for use in boilers, pressure or vacuum vessels, oil refineries, chemical plants, power generating stations, pumping stations, heat transfer systems, sanitary/waste water facilities, drip legs, and hydraulic systems.
Specific functional applications include low water cut-off, high or low alarm monitoring, and feed pump control. The controls feature hermetically sealed mercury switch contacts or snap-action contacts to manage liquid levels in large or small tanks.
Operating Conditions & Performance
The Series 500 operates with a maximum process temperature of 425°F (218°C) and an ambient operating temperature up to 212°F (100°C). Pressure ratings vary by configuration: the series supports pressures to 300 PSIG generally, while specific chamber/float combinations allow for pressure ratings up to 400 psig (28 bar).
Measurement capabilities depend on float rod length and float geometry. Single-stage configurations with a 2½" ball float support minimum specific gravities of .80 at 6" rod lengths, increasing to 1.1 at 24" rod lengths. Using a 2½" x 4" float in single-stage applications lowers the minimum specific gravity requirement to .55 (at 6") and .70 (at 24"). Two-stage configurations utilize only the 2½" x 4" float, with minimum specific gravities ranging from .70 at 6" rod length to .8 at 24".
Float rods are available in lengths of 6", 12", 18", and 24". The adjustable differential 'D' for single-stage units ranges from a minimum of ½" (at 6") to 2" (at 24"). Two-stage differentials are not adjustable, with values specified per rod length in the technical documentation.
Enclosure and Environmental Ratings
The series offers multiple enclosure types including General Purpose (NEMA-1), Weatherproof (suitable for NEMA 1, 2, 3, 4, 4X), Explosion Proof (NEMA 7, 9; Class I Groups B, C, D; Class II Groups E, F, G, Division I and II), and Explosion Proof/Vapor Proof. Approvals include UL listing for specific configurations.
Configuration Options
The Series 500 is configurable across construction type, enclosure rating, switch circuitry, chamber material, and float options to meet diverse installation requirements.
Construction and Process Connections
- Type 500T: Threaded connection with a 2½" NPT male pipe thread. Chambers are available in cast iron (C), cast steel (C1), or cast 316 stainless steel (C216).
- Type 500F: Flanged direct mount process connection. Standard flanges include ANSI 2½" 125 lb. cast iron, with options for ANSI 2½" 150 lb. forged carbon steel or 316 stainless steel.
Switch Types and Electrical Ratings
The series supports Mercury Contacts (SP-ST, SP-DT, DP-ST, DP-DT) and Snap-Action Contacts (SP-DT, DP-DT). Hermetically sealed snap switches are available for specific circuit codes. Electrical ratings vary by switch type:
- Mercury Contacts: Ratings include 10A at AC 120V/DC 30V and 5A at AC 240V/DC 125V for SP-ST configurations. DP-DT two switch ratings are typically 4A at AC 120V.
- Snap-Action Contacts: Ratings include up to 12A at AC 120V and 3† A at AC 440V for specific SP-DT configurations. DC ratings vary, with some snap-action types rated at 0.5** A (DC 125V) or 10‡ A depending on the circuit code.
Materials and Options
Wetted materials include cast iron, cast steel, and cast 316 stainless steel chambers. The series features a removable float and trim made of 316SS (stainless steel). Float options include the standard 2½" ball float or the larger 2½" x 4" cylindrical float.
Additional configurable options include:
- Semi-automatic operation with manual reset (identified by 'RU' after type number).
- Breather and drain for E-type enclosures, recommended for high humidity or outdoor service.
- A 3/4" NPT conduit connection that is rotatable 360° to facilitate wiring alignment.
Key Product Differences
The Series 500 distinguishes between Type 500T (threaded) and Type 500F (flanged) process connections. Chamber material selection directly impacts pressure ratings: cast iron, cast steel, or cast 316 stainless steel chambers paired with a 2½" ball float support up to 400 psig (28 bar), whereas the same chamber materials paired with a 2½" x 4" float are rated for pressures of 200 psig (14 bar).
Switch circuit variations include single-stage and two-stage configurations. Two-stage operation requires specific differential settings that are not adjustable, unlike the single-stage 'D' differential which is user-adjustable within specified limits per rod length.
PDFs & Manuals
Show Ratings & Reviews
| EXAMPLE | 500T | WT | 7810 | C | 55 | 6 | 0 | 500T-WT-7810-C-55-6-0 Liquid Level Control, NEMA 4X weatherproof enclosure, 2-1/2” NPT cast steel threaded chamber for direct tank mounting, SPDT snap action switch, fixed deadband, automatic reset, operating pressure 200psi (14 bar) to 425°F (218°C), minimum specific gravity 0.55 with 6” (152mm) float rod and 2-1/2” x 4” (64mm x 102mm) float. | ||
| CONSTRUCTION | 500T | NPT threaded process connection | ||||||||
| 500F | Flanged direct mount process connection | |||||||||
| ENCLOSURE | G | General purpose, NEMA 1 | ||||||||
| WT | Watertight NEMA 4, 4X | |||||||||
| E | Explosion-proof, NEMA 7, 9 | |||||||||
| EV | Explosion-proof, vapor-proof, NEMA 7, 9 | |||||||||
| CIRCUITS (for electrical circuits, See charts A & B below) |
XXXX | XX | Snap action or mercury switch, see chart A and B below. | |||||||
| 78XXHM | Hermetically sealed snap switch, see chart B below or consult factory. | |||||||||
| CHAMBER MATERIAL | C | Cast iron | ||||||||
| C216 | Cast 316SS | |||||||||
| C217 | Cast 316SS with shielded armature | |||||||||
| MINIMUM SPECIFIC GRAVITY |
80 | 0.80 specific gravity, 2-1/2” diameter round float | ||||||||
| 70 | 0.70 specific gravity, 2-1/2” x 4” float (2 stage only) | |||||||||
| 55 | 0.55 specific gravity, 2-1/2” x 4” float | |||||||||
| ROD LENGTH | 6 | 6” 316SS (Standard) | ||||||||
| 12 | 12” 316SS | |||||||||
| 18 | 18” 316SS | |||||||||
| 24 | 24” 316SS | |||||||||
| FLANGE | 0 | No flange | ||||||||
| 2 | 2-1/2” 125# cast iron | |||||||||
| 6 | 2-1/2” 150# forged steel | |||||||||
| 7 | 3” 150# forged steel | |||||||||
| 8 | 4” 150# forged steel | |||||||||
| 9 | 6” 150# forged steel | |||||||||
| 10 | 2-1/2” 300# forged steel | |||||||||
| 11 | 3” 300# forged steel | |||||||||
| 6S | 2-1/2” 150# 316SS | |||||||||
| 7S | 3” 150# 316SS | |||||||||
| 8S | 4” 150# 316SS | |||||||||
| OPTIONS | HF | Heat fins | ||||||||
| STW | Stainless steel tag wired | |||||||||
| 01 | Breather only (E-Housing only) | |||||||||
| 02 | Drain only (E-Housing only) | |||||||||
| 12 | Breather and drain (E-Housing only) | |||||||||
| 23720 | Fungus proofing special 23720 |
CHARTS A & B - ELECTRICAL CIRCUITS AND RATINGS
| SWITCH TYPE | SWITCH ACTION | ELECTRICAL RATINGS IN AMPS | ORDERING CODE | |
|||||||
| AC | DC | SINGLE STAGE | TWO STAGE | ||||||||
| 120V | 240V | 440V | 30V | 125V | 250V | LOWER | UPPER | ||||
| CHART A Mercury Contacts |
SP-ST open on level FALL | 10 | 5 | 3† | 10 | 5 | -4820 | -4820 | -20 | UL | |
| SP-ST open on level RISE | 10 | 5 | 3† | 10 | 5 | -4821 | -4821 | -21 | UL | ||
| SP-DT one switch | 4 | 2 | 1† | 4 | 2 | -4810 | -4810 | -10 | UL | ||
| SP-DT two switches E.I.* | 10 | 5 | 3† | 10 | 5 | -4815 | -4815 | -15 | UL | ||
| DP-ST two switches E.I.* open on level FALL | 10 | 5 | 3† | 10 | 5 | -4814 | -4814 | -14 | UL | ||
| DP-ST two switches E.I.* open on level RISE | 10 | 5 | 3† | 10 | 5 | -4813 | -4813 | -4813 | UL | ||
| DP-DT two SP-DT switches | 4 | 2 | 1† | 4 | 2 | -4806 | -4806 | -06 | UL | ||
| CHART B snap action contacts |
SP-DT one switch | 12 | 5 | 3† | 0.5** | 0.25** | -7810 | -7810 | -10 | UL | |
| DP-DT Two SP-DT switches | 12 | 5 | 3† | 0.5** | 0.25** | -7806 | -7806 | -06 | UL | ||
| SP-DT one hermetically sealed switch | 5 | 5 | 5** | -7810HM | -7810HM | -10HM | |||||
| DP-DT two hermetically sealed SP-DT switches | 5 | 5 | 5** | -7806HM | -7806HM | -06HM | |||||
| DP-DT two SP-DT switches | 10 | 3 | 10‡ | 3‡ | -9806 | -9806 | -06 | ||||
| SP-DT one switch | 10 | 3 | 10‡ | 3‡ | -9810 | -9810 | -10 | ||||
†Available on special order, change 1st digit in ordering code from 4 to 5 or 7 to 8, i.e., -4820 becomes -5820, -7810 becomes -8810, etc.
‡10 amp inductive (polarized) at 125 VDC.
*Electrically Independent.
**Resistive.